CA Solar Use Falling Because of Economics

mdsolar writes "The LA Time reports that California is seeing a big drop off in rebate applications for solar power systems. It seems that to get a rebate you have to also switch to a time of use rate with your utility. The math is not working out, especially for smaller systems that don't fully cover use during peak hours. The result: homeowners are reluctant to go with solar energy. 'The difference between peak and off-peak rates is particularly large in the 11 counties of Central, coastal and Southern California, where Edison provides electricity service to 13 million customers. Edison charges summer time-of-use rates that range from 29.7 to 35.9 cents per kilowatt-hour between 10 a.m. and 6 p.m. on weekdays. It drops to a range of 16.3 to 18.6 cents per kilowatt-hour from 10 p.m. to 6 a.m. weekdays and all weekend days and holidays, according to documents filed with the PUC.' There is likely an optimal system size that reduces consumer costs, but with things in flux you'd want some flexibility in your system."

Comments

Batteries

[athloi]

Can't you store off peak power, and then use it during peak times? People just aren't committed to the (expensive) environment.

Re:Batteries

[Anonymous Coward]

no...
try to guess how huge a battery you'd have to have to store the energy you consume during one day ;-)

Re:Batteries

[walt-sjc]

Peak means daytime. Solar only collects power during the day. The issue is that the panels were not collecting enough power to cover peak usage needs. Hence, there is nothing to store - it's all being used, and you still need to buy more at higher "peak" rates.

The biggest problem here is that solar panels are very expensive. You need a LOT to cover your usage unless you have also done MAJOR energy usage reduction efforts such as LED bulbs, better insulation, appliances, etc. If you don't take all those measures, the panel's don't make sense financially.

Re:Batteries

[Sobrique]

Googling says you can acquire a 32 amp hour, 12v sealed lead acid battery: http://store.sundancesolar.com/12vol33amsea.html Or, 384 watt-hours, if you prefer. Which'd run an 4 energy efficient 11W lights overnight, just about. But you can forget about having a hot shower, or a cup of coffee :)

Re:Batteries

[Anonymous Coward]

It is called a freezer or an air conditioning system. You drop a couple of degrees in hundreds of commercial freezers during the night and then they don't need power during the day. Basically, they act like a big battery. Of course, this could apply to any energy intensive task that you can arbitrarily schedule (pumping water up a hill, refining silicon, etc.). This is where renewable technologies are useful, but why they also will never have >10% share of energy production.

Re:Batteries

[Firethorn]

Storing power is expensive. You'd need a battery charging system and inverter, as well as some sort of system capable of detecting when to switch from charging to delivering power.

Besides, it's not 100% efficient by any means.

16.3 cents per kw/h. Most systems would be lucky to achieve 80% efficiency*, so a 'stored' kw/h would actually cost 20.4 cents. Then there's the fact that most lead-acid battery systems end up costing ~8 cents per kw/h stored, amortizing over their life, because you have to replace them periodically. So you're up to 28.4 cents, vs 29.7 cents for the peak power. Considering the capital costs to install all this, it's not worth it. Drop the efficiency to a more realistic 60% and the costs become 35.2. Youch.

NiMH might be better, but is more expensive initially. LiIon is the most expensive, degrades over time whether you use it or not, but has the highest efficiency.

Now, oversizing your solar panel arrays and having the storage systems so you can go off-grid entirely, also expensive enough that it's probably not worth it. You still generally end up getting special high efficiency DC appliances and doing your cooking and drying with gas.

As a side note, to show the vast difference between areas, my power is ~8 cents/kwh. Off-peak, if I had it installed, is 4 cents including fuel charge. And people wonder why I'm willing to let the californians install this stuff first. ;)

Answer: With my almost absurbly cheap power, combined with very little in the way of rebates, it just doesn't make economic sense.

*Efficiency in this case is a combined metric of battery, charging system, and inverter efficiencies.

Re:Batteries

[phantomcircuit]

I believe he was referring to storing off peak power from the grid, and not from the solar panels.

Which makes perfect sense, cheaper and collected at the time when solar panels cannot produce current.

Re:Batteries

[Lumpy]

That's the expensive way to do it.

the cheapest way is using a Syncing controller and you feed your power generated back to the Grid during the day running your meter backwards and giving the utility your extra wattage to make up for heavy use.

Problem is these new "laws" and "policies" make it so you either have to buy the big system that can store your power during the day causing the TCO of the whole system to go up dramatically as well as the required IQ for the homeowner as they now have to pay attention to batteries, and other items.

It's simply BS being pulled to discourage the use of alternative home generated power.

Re:Batteries

[Gordonjcp]

Just as a frame of reference, a 32Ah 12v battery is a small car battery. The battery in most cars is around 45Ah. Of course for this application you'd want a "deep cycle" battery that won't be damaged by being run nearly flat and then charged hard - these are sold for caravans and boats. They're more expensive than normal car batteries (about £1 per Ah), but they will last longer in this situation. Some companies actually do batteries specifically for solar power applications, but I don't know what makes them different from normal deep-cycle batteries.

Re:Batteries

[athloi]

Yes, I know that. My question is: if you're paying for power from the power company to supplement your solar system, can't you use off-peak power company power, store it in batteries, and use that to supplement your solar panels?

Re:Batteries

[ArmorFiend]

If you're always consuming power, never producing, what's the point of telling the electric company that you even have your own generation capacity? Just use the regular rates, and they'll be none the wiser. Seems like a non-story to me.

Re:Batteries

[EaglemanBSA]

You need to be careful when doing straight calculations like that - the big problem with lead-acid batteries is that their discharge is highly nonlinear. In other words if I have a 32 amp hour, 12-volt battery, if I drain it very slowly (a few amps only), I'll get the equivalent of 32 amp-hours out of it. If I were to draw, say, 32 amps out of it, it would be dead in much less (probably around 35 minutes') time. There are much larger capacities available, but the big problem with this is that A.) The batteries may be affordable, but the control systems are definitely not and B.) the conversion from DC to AC will also kill your storage efficiency. We ran into some of these problems trying to design such a system for a house in a developing community in Ghana.

Re:Batteries

[CreatureComfort]

Because there are economic incentives to use solar paid by the state, via the power company. If you want that $3,000 incentive you have to tell the electric company, but when you do, they jack your rates. Basically the article is showing that the amount the electric company jacks the rates means that, in general, it will remain financially better for most homeowners to stay full time customers of the utility. Now who would have thought they would do that?

Re:Batteries

[Gordonjcp]

Let's see. My house is currently pulling down around 0.5kW, but then it's daytime so there are no lights on, and I'm not boiling the kettle or anything.
Off-peak here is 11 hours per day, so I'd need to sustain something like 1kW (at a guess) 13 hours - let's call it 15 for a bit of slack. No, sod it, let's go for a full 24-hour supply at an average of 1kW (I don't have a lot of heavy electrical appliances that run during the day). So that's 24kW/h - and I suspect I'm guessing high there.

Right, let's consider our power delivery system. Forget 12v, to reduce the current draw I'm going to use 24v electrics. This page has a range of 24v to 240v inverters. They run at around 90% efficiency (inverters are very good these days). Lets assume a full load draw of 50A - that's 1200Ah. LED lighting tends to be easier to get in 12V form, with GX53-type replacements being cheap and easy to get. They put out about the same light as a halogen lamp (maybe a little less) for an input power of less than 2W. At most they're going to pull down maybe 15A for a houseful. Let's for argument's sake say it's 10W, because that gives us a total load on the batteries of 60A. We'll split the lights across the batteries to even the load.

Still with me? Good. We have a total power requirement of 60A at 24v, for 24 hours. This is 1440Ah (it's also 1440kW/h, but that's just co-incidence. 24 volts, 24 hours). Let's go look at batteries.

A quick Google suggests the Elecsol 125 batteries might be the way to go - they're relatively cheap, small enough to be handled by one man (28kg - they're not light!) and not too expensive (a little below the £1/Ah price point). With 125Ah capacity, we'll need 24 to cover our day's requirements.

These are 34x17x24cm, and this is where my crappy arithmetic and geometry fails me. I could arrange them on a special stand about 102x68x80cm, or very roughly the size of a small chest freezer. You'd need a bit more room for the services board, and some switchgear, the inverter and the regulator. You'd still easily fit it in your garage, though.

Re:Batteries

[petermgreen]

the cheapest way is using a Syncing controller and you feed your power generated back to the Grid during the day running your meter backwards and giving the utility your extra wattage to make up for heavy use.

The grid is not a battery! All that a net metering system that doesn't discriminate the value of units based on the time of day will do is move the burden of power at the wrong time onto someone who isn't being paid to handle it.

the utilties have mostly tollerated this so far because there isn't enough of it for them to really notice but if using the grid as a battery were to become the norm then they'd be in real shit.

Re:Batteries

[HeyMe]

The power companies told the legislature that they were getting screwed because they had to buy the power from home generators at retail (the same rate(s) they charged the homeowners) and sell the excess at wholesale rates. They got the legislature and PUC to change the rate structure to allow them to charge home generators commercial (time-of-use) rates, which is good for the power companies because most home generators do not generate enough to cover their needs at peak times (especially during the summer cooling season). Of course, since people are not (quite?) as stupid as some make them out to be, the law of unintended consequences kicks in. Homeowners do the math and do not install solar systems and the power companies lose out on all that peak time generating capacity those systems would have freed up, and all the lovely money they could have charged for it. Oh, the joys of artificial economics.

Now, if any of the 3 or 4 "new solar technologies" that promise more conversion efficiency and/or radically lower production and deployment costs (and seen on this board) come to fruition, we will see "solar roofs" all over the place, without the need for artificial incentives.

Re:Batteries

[Anonymous Coward]

I believe he was referring to storing off peak power from the grid, and not from the solar panels.

He may have been but unfortunately FTFA:

The unintended glitch was created in December, when the PUC moved to implement the law by requiring that solar users switch to the higher "time of use" rates for their supplemental electricity.

The PUC messed this up, the Terminator should pay them a visit.

Re:Batteries

[NeutronCowboy]

Just like with what we're seeing with cars right now (energy-efficient cars becoming hot sellers due to a quadrupling of gas prices here in CA), home energy will become interesting for the masses only when energy prices rise from their current levels.

I currently spend $20 a month on electricity (no AC, no washer and drier, no washing machine though), so for me, anything outside of a small windturbine would be completely inefficient. I'm actually hoping that we a) ditch our efforts to secure large imports of cheap oil and b) ditch our efforts to subsidize home fossil fuel extraction (which includes biofuels from ethanol, btw). If we're serious about energy independence, we first have to have an incentive to be that - and free markets are, unfortunately, the most efficient way to get there.

Re:Batteries

[mcostas]

Going solar and using peak pricing make perfect sense. Solar peak output follows demand perfectly. Most home solar installations will generate far more at peak times than is used. At noon on a hot day, I'm at work and my house is using nearly zero power. But the solar panels are cranking out 3kW, which is running the meter backwards at PEAK prices. The only time you're drawing much from the grid would be night, when electricity is cheap. The only problem with the current situation is that the millions of the non-solar homes are being allowed to buy electricity at flat subsidized prices. Everyone should pay peak and off-peak rates.

Re:Batteries

[misleb]

I think batteries and their regulating circuits are pretty expensive. I mean, look how little time you get out of a UPS. I've got a big ol' UPS at work powering two racks with two external battery packs and I can only get about an hour out of it. Add to this the fact that Lead/Acid batteries don't like being drained/charged regularly (read: you'll need to replace them regularly), and you've got a very expensive and high maintenance system on your hands.

-matthew

Re:Batteries

[giafly]

The biggest problem here is that solar panels are very expensive. You need a LOT to cover your usage unless you have also done MAJOR energy usage reduction efforts such as LED bulbs, better insulation, appliances, etc. If you don't take all those measures, the panel's don't make sense financially.

Unfortunately, whatever energy reduction measures you take, it will not make sense to buy expensive solar panels. My neighbour spent $40K and saves almost nothing. Plant some fruit trees to give shade/reduce wind-chill, donate half the remaining money to a charity that stops pollution in the third world, and use the other half to buy solar in five years time when it's cheap.

Re:Batteries

[Alioth]

If people were committed to the environment and energy saving, they'd at least be picking the low hanging energy saving fruit. Most people can probably save more energy by using a bicycle or public transport to get to work and back instead of driving their car - things that are cheap (certainly in the case of the bicycle) and exist right now. But they don't. They don't even go for energy efficient cars - they buy the most inefficient vehicle they can afford.

To the majority, saving energy is somewhat below having a nice haircut in the priority list.

Re:Batteries

[Courageous]

*shrug*

Doesn't matter in the small. Peak use is when the power providers have the worst time providing power. Having a little solar... or even a lot of solar... out in cogeneration land just relieves the primary power plants of generation requirements.

C//

Re:Batteries

[WormholeFiend]

But you can forget about having a hot shower, or a cup of coffee :)

For my hot water needs, I'm planning on installing a solar water heater system, and store pre-heated water in a 2nd tank next to the main (natural gas) water heater.

The systems I'm looking at are designed to work even in winter (in sunny conditions, of course), and automated to work when the conditions are right.

These systems are just about the cheapest green alternatives one can get.

Re:Batteries

[dougmc]

My neighbour spent $40K and saves almost nothing.

Then your neighbor must have really screwed it up. $40k worth of solar panels should, properly installed, cover a large part of your electric bill. Granted, it may not be cost effective, as $40k will pay for many years worth of electrical bills for most people -- but even so, he should save a whole lot more than almost nothing.

Now, if `saves almost nothing' means that the money saved on electricity is offset entirely by the payments made on that $40k, then that's a different matter, and he did well -- breaking even with solar power is hard to do in most cases. And eventually the system will be paid off. And as an added bonus, when something goes wrong and everybody else loses power ... your neighbor will still have it. At least during the day.

Re:Batteries

[srmalloy]

And that's fine if you live alone, so virtually everything the solar generation system produces while you're off at work can be pumped back into the grid (and the energy consumption from always-on appliances like your refrigerator is not 'nearly zero'); a family is going to have higher energy consumption through the day. But the problem is that under the tiered pricing mechanism, energy costs double during the peak period. If you can't afford to put in a solar generation system that will produce at least half your energy consumption during the peak period, then your energy bill will go up as a result of your being forced to the tiered-cost structure when you install a solar generation system. And remember that it is the average energy production that determines whether you break even or come out ahead on the arrangement, and it's dependent on the weather, which you can't control; Cal Edison doesn't care that your solar panels are parked under a cloud all day; you pay the same doubled rate for peak power regardless, and if you're not generating enough power yourself, that's your problem.

Re:Batteries

[Locutus]

That surely is ONE problem but this article brings up another BIG PROBLEM and that is with the utilities. They do not want solar power to be cost effective for home and business owners. This also explains why these same utilities tricked the PUC into letting them charge customers for new ToU digital meters. It won't be long before the PUC is asked to allow the utilities to switch home owners to ToU metering like most businesses already are. Bingo, a nice big profit increase and the people helped fund it.

Nice work PUC. Not!

LoB

Re:Batteries

[Locutus]

Well said and it's good to see another who cheers higher priced energy.

LoB

Re:Batteries

[Control Group]

Add to this the fact that Lead/Acid batteries don't like being drained/charged regularly

Really? I thought that was exactly what they were good at - being able to deliver a large percentage of their charge at once, then take a recharge (which is why you use them in cars, since that's the profile of electrically starting an ICE).

My car battery cranks out 12 volts at 400 amps for a couple seconds at least twice a day, then recharges real well over fifteen minutes.

Now, if you're talking about draining them completely flat, you're 100% correct. A steady drain down to empty is one of the worst things you can do to a lead-acid battery. But that just means you have to plan your battery capacity such that the expected load doesn't empty them completely.

Re:Batteries

[Lumpy]

since you do not know howe any of this works and are making things up based on assumptions please let me enlighten you.

Syncing controllers feed power BACK to the system to hel the power companies during peak daytime hours. contrary to your understanding from 8:00am until 5:00pm the most power is being used, having solar back-feed with the RIGHT gear helps the grid greatly reduce loads. These controllers do it very safely and are specified by the power companies. if they dont see voltage from the line side they shut down until they are manually reset.

these systems are proven and in use everywhere. Just because you dont know anythign at all about the subject and jump to some really wild conclusions does not mean the power companies do.

The power companies STOPPED giving solar people the payback at the higher daytime feed rates but giving them the backfeed rates at the cheaper off-peak while they resell that solar power at the higher premium-plus-peak rates. It's a cash grab and nothing more.

Re:Batteries

[Anonymous Coward]

Having installed solar aux power on a number of boats and one cabin, I can tell you that 80% is way better than what exists -- the rule of thumb is start at 50% and work your way down (for a battery-inverter system).

I've so far only ever used LA batteries though, so if you have extra cash for better accumulators, you may get a better rate. Generally it's the inverters that kill you -- you want to run as much stuff as possible on whatever DC voltage you standardize on, I prefer 12V because car accessories are easy to find.

Re:Batteries

[misleb]

Now, if you're talking about draining them completely flat, you're 100% correct. A steady drain down to empty is one of the worst things you can do to a lead-acid battery. But that just means you have to plan your battery capacity such that the expected load doesn't empty them completely.

Right, and my point is that this makes the proposition that much more expensive. I mean, it would be expensive enough just getting enough batteries to run a home for 12 hours. Then double that to make sure you don't have to drain them 100% to do it.

THEN add in the fact that such a system would only be about 80% efficient at best. You'd be lucky to break even over many years.

Of course, it might be nice to have one big UPS for your home if you live in a place were power was unstable. Especially if your internet connection didn't depend on the power (DSL i know still works when there is no power to your home).

-matthew

Re:Batteries

[Control Group]

Got it. And you're completely correct; I can't imagine it's even close to economically viable to try and power your home off a battery array. Not to mention the potential risk of storing dozens of car batteries in your basement - house fires leap to mind, and the possibility of a dead short.

Or, of course, user stupidity. Some years back, I saw someone with take a UPS and plug it into itself, with some fairly interesting results. To some extent, this can be engineered around - I'm pretty sure modern UPSes are designed to prevent spectacular failure in the event of plugging them into themselves, but I haven't been involved in DC design in a while - but we all know how the race between idiot-proofing and better idiots goes.

You'd be better off, I think, spinning up a flywheel array than trying to store energy in a room full of car batteries.

Re:Batteries

[Anonymous Coward]

It's the AREA of the ROOF for the PANELS that generally limit the available power -- in CA, AC is a requirement.

Re:Batteries

[grumpygrodyguy]

Can't you store off peak power, and then use it during peak times? People just aren't committed to the (expensive) environment. ...

"no...
try to guess how huge a battery you'd have to have to store the energy you consume during one day ;-)"

Actually you can.

I researched this several years ago when I was designing an "off the grid" home. One solution is based on the flywheel. The idea is to pour a very heavy, precisely balanced, cylinder of concrete and bury it underground near the foundation of the home. The cylinder is then suspended on magnetic bearings and uses magnetic induction to store electricity in the form of rotational kinetic energy. This stored energy could then be withdrawn from the flywheel by reversing the magnetic induction effect to induce current. Devices like these have been in use for several years now at large industrial facilities. They are usually employed as a UPS(Uninterruptible power supply) in the event of a blackout.

The only problem with these devices besides the cost of installation is the need for ground stability. So in this case, many Californians near a faultline would find this solution impractical.

Re:Batteries

[Damvan]

Given the cost of the batteries and the charge controllers, as well as the loses that occur when converting from AC to DC back to AC, and the lost energy due to the fact that you can't discharge the batteries 100%, there would have to be a pretty significant difference in the cost of peak vs non-peak to make this viable.

Re:Batteries

[Damvan]

"everybody else loses power ... your neighbor will still have it. At least during the day."

This does not apply for most grid-tied solar installations. In order to protect electrical workers, the grid-tied inverters will shut down production of electricity when they detect that the grid side has gone down. So if a transformer blows up in the neighborhood, the workers show up to fix it, they won't get shocked by power being fed into the system by my solar array. In addition, Edison required a seperate and accessible disconnect so they could shut down production if necessary. In the event of a black out, I am without power just like everyone else, despite the 3.2 kw solar array on the roof.

Re:Batteries

[Anonymous Coward]

Why couldn't you just put an auto trip relay, like they do with standby generators. That way when you lose power it disconnects your house from the main power and closes the bypass circuit to the generator. Thus your house has power, and is electrically isolated from the grid.

Re:Batteries

[bcrowell]

Can't you store off peak power, and then use it during peak times?
There are two types of systems: off-grid, and grid-tied. An off-grid system is what people get in rural areas where there's no other way to get electricity. It includes a battery, which is big, expensive, and requires careful maintenance. In urban areas, a grid-tied system makes much more economic sense, so no, it isn't economically feasible for an urban homeowner to store the power and use it later at off-peak times. Also, you can't really store off-peak power with a PV system, because peak hours are during the day, which is when the sun is up.

In addition to all that, there's the situation in California that TFA describes, where if you get a PV system, they force you to switch to a less advantageous billing system.

Re:Batteries

[arodland]

Most people... you have no clue. Most people could get to work on a bike in about two hours... assuming they're fit enough to bike for two hours, anyway. And public transport? What public transport? :)

Re:Batteries

[Shajenko42]

Most people can probably save more energy by using a bicycle or public transport to get to work and back instead of driving their car - things that are cheap (certainly in the case of the bicycle) and exist right now.

They can't where I live. Many, many people in Dallas live a good distance from their work, and have to travel over the highway, so biking simply isn't an option. Public transport would at least triple my commute (from 30 minutes to an hour and a half, each way), even though DART has a bus that stops right at the front of the building.

When cars aren't nearly so much more flexible than public transport, you'll get more people using them.

Re:Batteries

[mdsolar]

You can get this arranged so that you do get the power even with the anti-islanding in effect. This is standard on systems we offer: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Re:Batteries

[skintigh2]

They don't "jack up" your rates, they change the way you get billed. Instead of paying a medium amount day and night, you pay a high amount during the day and a low amount at night.

If you go to work during the day and generate 1kWh to put into the grid, at night you use 2 or 3kWh from the grid and not pay a thing. So, for some people they've doubled or tripled the value of solar panels.

Now, if you stay home with the kids and use AC all day, you're screwed.

Obviously, someone didn't think this through. But I highly doubt it was intentional. I don't think anyone benefits from frequent blackouts during the summer.

Re:Batteries

[CreatureComfort]

The electric lobby got legislation passed that requires people who install solar panels to switch rate plans. The new plan they are forced to use prices electricity low during the times of day when the power they would produce is at its maximum and usage at its lowest, so power would be flowing into the grid and the electric company would have to pay the person. Then prices electricity high during the times when power generation is low and use is high when it is very likely that power will need to be drawn from the grid.

If they could stay at a flat rate, your example would be valid. However, in reality, the variable rate plan means you have to change the kWh in your example to dollars. So your example actually should read:

If you go to work during the day and generate $0.16 (1kWh * $0.16/kWh) to put into the grid, at night you use $0.56-$0.96 (2 or 3kWh * $0.24/kWh to $0.32/kWh) from the grid, thus maximizing electric company profit.

If you think that this wasn't deliberate and calculated out to the last fractional cent by the electrical generators prior to setting their lobbyists loose, well, bless your innocent heart.

Re:Batteries

[Dun Malg]

It is called a freezer or an air conditioning system. You drop a couple of degrees in hundreds of commercial freezers during the night and then they don't need power during the day. Basically, they act like a big battery. They only act as a "battery" within themselves. The current discussion is about storing off-peak electricity for use during peak times. You cannot draw those 2 degrees out of the freezer to run your microwave.

Re:Batteries

[Alioth]

They can always move closer to work, or get a job closer to home. I still assert that to most people, energy saving is a pretty low priority. It's fine to have a list of priorities, but people crow about how we ought to be saving energy, but then live so far away from work that it's impractical to get there by any other means than private car - then compound it by buying a giant SUV.

Re:Batteries

[Alioth]

Evidently, saving energy to these people is a lower priority than finding a job closer to home, or a home closer to the job. That's what my post was about: saving energy is a pretty low priority to most people because they are unwilling to even pick the low hanging fruit, which includes (but is not limited to) using public transport, using a bike, or using a fuel efficient car. I can't comment about your particular situation (maybe you drive a car that gets 50 mpg), but looking around me, half the cars on the commute to work are giant SUVs with one person in them. Many of these people go on about how we should be saving energy - but I guess they expect others to do the energy saving if their daily drive to work is a Suburban that gets 8mpg on the commute.

Texas is a state that exemplifies this: giant fullsize pickup trucks with nothing but one driver (probably in a suit) and an empty truck bed that has never seen an ounce of horse shit. (I've even seen a pick up truck limousine in Houston!) The second car that people have is often also a giant SUV. The same people are feeling so good about fitting CF lights - yet they could save more energy in a week than all the light bulbs in their house in a year simply by commuting in something like a Volkswagen TDi instead of a giant Chevy Silverado. Just look around you - look how many gigantic vehicles are on the road in Dallas, often with just the driver. Look how many people drive huge pickups in Dallas with spotlessly clean truck beds.

Re:Batteries

[cbacba]

Actually, at 39c/kwh for peak costs, they're starting to sound better. That's 3x what we pay for a kwh, anytime of the day or night. With tax rebates paying lots of the costs, it's no wonder some are considering and even doing such a thing.

Adding the batteries would make efficiencies much lower and increase initial and maintenance costs substantially.

Perhaps with a factor of 10 reduction in photovoltaics costs, they'll be quite resonable to implement.

Re:Batteries

[skintigh2]

Your mass is bass ackwards

From the summary: "Edison charges summer time-of-use rates that range from 29.7 to 35.9 cents per kilowatt-hour between 10 a.m. and 6 p.m. on weekdays. It drops to a range of 16.3 to 18.6 cents per kilowatt-hour from 10 p.m. to 6 a.m."

1kWh during the day = up to 35.9 cents which at night = up to 35.9/16.3=2.2kWh.

Next time you want to be condescending make sure you aren't dead wrong about everything or else you look like a real jackass.

Re:Batteries

[Shajenko42]

Evidently, saving energy to these people is a lower priority than finding a job closer to home, or a home closer to the job. That's what my post was about: saving energy is a pretty low priority to most people because they are unwilling to even pick the low hanging fruit, which includes (but is not limited to) using public transport, using a bike, or using a fuel efficient car.

This isn't low-hanging fruit - this is a serious change for a lot of people. Low-hanging fruit would be changing your light bulbs, or turning off the lights more often, or using a pot lid when you boil water. Changing jobs or homes doesn't count.

The same people are feeling so good about fitting CF lights - yet they could save more energy in a week than all the light bulbs in their house in a year simply by commuting in something like a Volkswagen TDi instead of a giant Chevy Silverado.

You really don't seem to know what "low-hanging fruit" means. It means that it's the easiest things you can do to save energy, not the ones that will yield the biggest energy savings. This means that if you want people to do something, you'd better make it worth the trouble. Cities have to be designed better to allow for mass transit to be more efficient.

Just look around you - look how many gigantic vehicles are on the road in Dallas, often with just the driver.

Having a giant SUV for many people is a matter of safety - you can't control what cars other people drive, only your own. And if having a bigger car greatly increases one's odds of walking away from an accident alive, then that's the smart move. (I don't drive one, personally) I'd love to be able to use the train/buses to get to work in back - it would save me a lot of money and stress on the road. But it's not worth a three hour a day commute.

Re:Batteries

[Alioth]

Oh come on, changing your car isn't all that hard. Compared to the technical challenges required to make available affordable solar power or storage systems, it's absolutely trivial and it's absolutely low hanging fruit of energy saving. Last time I bought a new car it took a *whole afternoon*. That's not exactly a giant effort. Changing a giant SUV for a fuel efficient car absolutely is low hanging fruit - especially if you're buying a new vehicle anyway (I don't know anyone who intends to drive the same vehicle for the rest of their lives). It's just not that hard. The lifestyle change (well, except the keeping-up-with-the-joneses image) is practically nil.

SUVs also have been shown to be no safer than a car. Don't forget that cars have to pass stringent safety tests. In many cases, when all options are considered, SUVs turn out to be more dangerous in a collision for the occupants - it's just PERCIEVED safety that doesn't really exist.

There's nothing wrong with having priorities in life, and I won't criticise someone for what their daily drive is. However, if they go on about how they are doing so much to save energy, and how much others should also be saving energy, and how they are waiting hopefully for $MYTHICAL_BREAKTHROUGH in solar technology, yet they drive a Chevy Suburban mostly with just one person on board, well, I think they are fair game. Especially, when they come to sell that SUV and buy something new, it's another giant 8mpg SUV. There's too much of this "real energy saving is someone else's problem", or "the government should wave a magic wand and make it all go away, but without making me change my lifestyle" around.

Whither predictions?

[dazedNconfuzed]

So where's the cheap per-watt solar panels we've long been promised?

Re:Whither predictions?

[OwnedByTwoCats]

I don't know.

What the newspaper article fails to report is what the "flat rate" charge is for electricity. It says customers going for the solar rebate have to have the time-based charges for electricity: 25 to 30 cents per kilowatt hour 10 am to ? pm, and 18 to 20 cents at night. But what is the charge that they were paying? Doesn't say.

Why isn't the electric utility installing large solar panels to generate electricity during peak hours? Because that takes more money than burning fossil fuels in power plants? They could get creative e.g. leaing rooftop space from homeowners.

Re:Whither predictions?

[Moofie]

"Why isn't the electric utility installing large solar panels to generate electricity during peak hours?"

Because the electric companies know that PV cells don't give a good ROI, except if and when you can game the electric companies into subsidizing them for you.

Re:Whither predictions?

[Firethorn]

Why isn't the electric utility installing large solar panels to generate electricity during peak hours? Because that takes more money than burning fossil fuels in power plants?

Exactly. Burning fossil fuels in power plants is an extremely cheap method of power. It can generate power at a cost of ~4cents/kwh. Nuclear is something like 3.9 average. This includes production and capital costs, from the chart on this page(scroll down), actual production costs are only ~2 cents, with nuclear edging below coal in 2000.

What kills solar is the install cost. There was an article about a canadian plant on slasdot recently, they were expecting it to cost $300 million for 40MW. Now, $300 million at 5% interest is 15 million a year. That's capital cost. I estimate that it'd produce 140 million kwh* a year. That's 10.7 cents per kwh for the capital costs alone, this does not include any plant costs.

10.7 cents vs. 4 cents? Tough sell

They could get creative e.g. leasing rooftop space from homeowners.

That would be a huge hassle, as they'd then be liable for everybody's roofs whenever a good storm comes through, as well as having to worry about climbing on 10k roofs to make repairs. It ends up being cheaper to buy property out somewhere and building a massive plant. Building owners can make it pay for such small installs because they're paying retail for electricity, not wholesale. Personally, I'd be installing a solar water heating system, preferably capable of heating the house as well. That's currently far more economical. Doesn't take much roof space either. If solar panels were a tenth of their current cost, it'd make far more sense.

*40MW plant, 40% load factor

Re:Whither predictions?

[pla]

Burning fossil fuels in power plants is an extremely cheap method of power. It can generate power at a cost of ~4cents/kwh.

Only if you completely ignore the environmental impact. Aside from the power plants themselves making most superfund sites look like nice places to take a picnic, what comes out of the smokestacks eventually lands somewhere.

Currently in Northern New England we have a huge mercury problem - Not because we put it there, nor even because our power plants made it (we have one of the highest percentages of hydro and nuclear in the country); Rather, because midwest power plants, with their nice big smoke stacks, end up dumping most of the acids and metals in the smoke on us as rain.

So if you want to include the cost of cleaning up each and every lake in ME/NH, I suspect it would come out a hell of a lot higher than $0.04/KWh.

Re:Whither predictions?

[Firethorn]

Ughhh... I knew I should of put a qualifier in there.

Regardless, until the feds hold the power plants to those standards(IE clean up your stacks or pay for the pollution), in raw economic terms they're cheaper.

Still, I've stated it before, but I'd shut down every coal power plant and replace it with nuclear if I could.

Much of the baseload demand could be taken care of with nuclear power, with solar/wind supplimenting, and hydro/geothermal being used for peak demands. I'd use the excess baseload power created by overbuilding on nuclear plants to produce hydrogen, ethanol, or whatever other fuel that'd end up being most economical.

Re:Whither predictions?

[Panaflex]

Making silicon solar panels isn't environmentally friendly either. In fact I'd venture that the environmental impact is as bad or worse than coal or nuclear. The amount of power, just necessary to make a solar panel is probably as much as it generates over a few years!

That said - I'm still a fan of Solar for limited applications with low-power requirements which replace chemical batteries. I'd rather see wind power and hydro for most household/industrial use - as it's much more efficient.

Re:Whither predictions?

[Anonymous Coward]

That Midwest let's blame them for everything. Or more exactly part of the Mercury outfall from 60 years of emissions by now defunct steel mills and almost defunct auto manufacturing. And yes some of the pollution in the Northeast is a result of manufacturing, etc in the Northeast.

Re:Whither predictions?

[Dachannien]

Rather, because midwest power plants, with their nice big smoke stacks, end up dumping most of the acids and metals in the smoke on us as rain.

Haha! Take that, yankees!

Re:Whither predictions?

[ambrosen]

Because they don't own the land to install them on? Because their facilities management process for their office blocks is complicated enough already?

Re:Whither predictions?

[JoeD]

We have to ignore the environmental impact, because it's not paid DIRECTLY by the generating entity.

If it were, then the "extremely cheap" adjective would not apply.

Re:Whither predictions?

[bcrowell]

Why isn't the electric utility installing large solar panels to generate electricity during peak hours?
They are, in some areas. There are some huge generating stations in San Bernardino County. Of course it helps that San Bernardino County is a desert, so land is cheap, and there's lots of sun.

It can generate power at a cost of ~4cents/kwh
That may be true in your area. Where I live, consumer rates are about 20 cents/kW.hr.

The biggest problem with the electric company building PV stations is that they'd have to buy land. As an individual homeowner, you already own the land, and the sunlight is just a resource that's hitting your house and being wasted until you put up PV panels. That's not to say that it makes economic sense for all homeowners, but for me, it comes out to be basically a financially neutral decision.

Re:Whither predictions?

[Anonymous Coward]

We Capitalists ignore externalities, thank you very much.

Re:Whither predictions?

[Firethorn]

That may be true in your area. Where I live, consumer rates are about 20 cents/kW.hr.

That's retail. I'm talking about national averages. Plus, especially if you're living in California, you're getting much of your power from natural gas fired turbines.

That's 7.5 cents per kwh to produce, then you have to account for distribution, taxes, etc...

Coal is cheap, nuclear is inexpensive and safe, wind and solar are very expensive and don't produce power on a demand schedule.

Re:Whither predictions?

[drix]

Worse than coal or nuclear is going a bit far considering the environmental impact of coal includes the destruction of entire ecosystem in West Virginia and the lion's share of the responsibility for global warming, and we all know how nice nuclear waste is. But you do have a point.

However... there's more than one way to skin a cat. PV is just one way to harness energy from the sun, and it's not even cheap, environmentally friendly, or efficient. Check out these guys. That's just mirrors and metal, and the world's neatest mechanical engine. I keep waiting for the day when people realize we can generate solar power for prices nearing that of fossil fuels, today, with no scary waste or CO2, but, alas, hasn't happened yet.

Re:Whither predictions?

[Panaflex]

Great link! I've always wondered if someone had actually done that.

I say worse than coal or nuclear only because if we seriously became a PV economy - the efficiency of PV is so low that it could never replace traditional generation in the end.

I like the Stirling engines, the biomass/algae systems, and of course wind. The obvious problem is that we can't scale these systems right now to match what is already available. With time, I'm sure we can do better.

Good question.

[Peter Trepan]

I haven't seen any of these solar setups before, but don't they already require arrays of batteries? Or do they just plug straight into the grid? If they use batteries, it should be relatively easy to modify them to use off-peak power during peak times. In fact, would it be cost effective to do this for homes without solar power?

Re:Good question.

[SQLGuru]

You have two options with solar, grid-tied and off-grid. Grid-tied is just that, a system that is tied to the power grid. Your meter runs forwards and backwards based on your load and your solar output (which should be impacted by the time of day rates -- it will only run backwards during peak times, so that should offset any need at night). Off-grid is the installation with the batteries. You store excess during the day to be used when there is no sun.

I don't think the time of use rate is such a problem. If you size your system correctly, it will be just as "economical" as it was.....(I use the term loosely because I haven't yet seen the numbers run favorable for anything less than 15 to 20 year payout even with a favorable rebate system). Just make sure that you use less than you generate during the day to offset a lot of your cost at night. Peak time is "daylight hours" which is when your system should be operating at its peak, too.

Layne

Re:Good question.

[maino82]

In most cases, the grid actually acts as your batteries, so when your panels are not generating (say at night) you pull power from the grid. This is a pretty common setup since if you ever have a string of low-production days (if it rains for a few days in a row or something), you're still covered electricity wise. The only places I've really seen people use battery system is in off-grid applications. If you're out in the middle of nowhere and can't get utility service (or don't want to rely on utility service) or if you're just fed up with the utility company and don't want to put up with their BS anymore. The downside of off-grid applications is that then if you have a string of low-production days you're pretty much dead in the water.

Re:Good question.

[Damvan]

I got quite a substantial rebate from Edison when I installed my solar system (3.2 kw). One condition of the rebate was that my system had to be grid-tied, I could not install any batteries. Of course, once their inspection was done, what they don't know won't hurt them...

Re:Good question.

[Dare nMc]

I don't think the time of use rate is such a problem. If you size your system correctly, it will be just as "economical" as it was..

I think you got it right, the rate essentially doubles during peek hours, so for your energy bill to go down you have to put in a big enough system to supply 1/2 of your power during peek (thats also when the suns out.)
but thats just to come out even, on the electric bill, you gotta go bigger than that to get payback.

Curious...

[packetmon]

According to the article... Embarrassed state officials are scrambling to fix the problem. Does this mean they'll revamp the fuzzy math to attract more (*cough* suckers*) wonderful customers?

Cost of Solar Powered Hardware $15,000
Tax rebate and reimbursement from state (50%) $7,500
$7,500 over 10 years $750

Hidden truths...
Property tax increase .1%
Environmental fuzzy save the birds you're killing from the reflection of your solar panels tax .2%
New-soon-to-be-imposed "Green Tax" .1%

So on a reverse Mastercard like commercial for the state and greased pocket goons:
Cost of Solar Powered Hardware $15,000
Suckered homeowners 10,000
Revenue in our pockets from suckered homeowners... Priceless

Re:Curious...

[MindStalker]

15K added upfront to the cost of a California home if virtually nothing. Problem of course is you need to put some money aside to pay for the eventual replacement, but in 10 years solar should be cheaper.

Re:Curious...

[Anonymous Coward]

Problem of course is you need to put some money aside to pay for the eventual replacement, but in 10 years solar should be cheaper.
The real question, though, is why you would replace a system with 60% of its useful life remaining?

Re:Curious...

[OldeTimeGeek]

Property tax increase .1%

You're obviously not a Californian. Post Proposition 13, improvements to your house that increase its value don't make your property tax go up. Only the homeowner by voting a special assessment, the local government State Legislature can and only then with a super-majority vote. If you sell the house, however, the next buyer's tax bill will get the full benefit of your improvements. Remodeling the kitchen has the same effect. Which one has a better possibility of lowering your electric bill?

Environmental fuzzy save the birds you're killing from the reflection of your solar panels tax .2%

Does this happen? A quick google seems to indicate that birds have a better chance of getting killed by chasing light on the other side of glass windows than being par-cooked by reflected light. The neighborhood cat kills more birds than the solar panels ever will.

Re:Curious...

[Anonymous Coward]

Because ya gotta upgrade, otherwise you're going to be behind and can't get those uberframraters... er, n/m.

Re:Curious...

[jjeffers]

> Environmental fuzzy save the birds you're killing from the reflection of your solar panels tax .2%

Reflection off the solar panels? A solar panel that is reflecting a significant amount of light isn't going to work as a solar panel very well. Killing birds? I've been working around solar panels for 10 years and I've never seen a dead bird around them.

Are you thinking of huge concentrating solar arrays out in the desert? These are relics from the past. The article is discussing small solar arrays on the roof or in the yard of a home or business. These are clean, low maintenance, long life-time items.

I would suggest you visit http://www.homepower.com/ for an introduction to solar.

Thanks,

-James Jarvis
APRS World, LLC

Re:Curious...

[anoopjohn]

but in 10 years solar should be cheaper One thing I can assure you is that in 10 years non solar power would be much more expensive

Re:Curious...

[Skye16]

That's because my cat is a god damned ninja. \m/ (-_-) \m/

Re:Curious...

[Anonymous Coward]

In California, new construction results in a reappraisal, which is likely to increase your property taxes for the value of the construction. My understanding is that if you do your own work, you get taxed on the value of your labor, even though you did not pay yourself.

However, my understanding is that solar construction is exempt from this reappraisal.

BTW - when I checked, the only way to get credit from the state was to have the work done by a contractor. DYIers need not apply.

Re:Curious...

[timjdot]

This article is not informed. I just read a HomePower article yesterday on this. The deal is to buy alot of panels (dude bought 48 I think) and sell power to the grid during peak when it is most expensive. Then buy your power when the lights are out. The dude ended up with a surplus of power he couldn't use (you can only sell back the amount of power you used to use before going solar according to what I read). Basically he _gave_ power to Edison and they sold it to someone else. His payoff was 7 years. The panels hold a 25 year warranty. The grid is the "battery".

Anyone is CA should be installing solar like this. I'd do it here in NC if I got a tax credit like CA and my HOA would allow it. I'm thinking the USA should pass a law like the DirecTV that says an HOA cannot penalize for solar panels and hot water panels.

Re:Curious...

[srmalloy]

Ahh... And because one person was able to push power back to Cal Edison and pay off his investment in seven years, this means that everyone who installs solar generation systems will be able to do the same? By the same argument, if I get to pick a single person for a sample of the population, everyone in the US is a multibillionaire, because Bill Gates is a multibillionaire. To be valid, you need to look at all the people who have installed solar generation systems and look at their aggregate performance to determine whether it is, overall, a net benefit. HomePower isn't about to print an article about someone who installed $15,000 of solar-generation hardware and had their power bill go up because they weren't generating enough power to offset Cal Edison's tiered pricing system; that wouldn't support the premise of the publication.

Re:Curious...

[Anonymous Coward]

Check you state laws. Here in FL HOAs would try to block solar panels, but the state stepped in an outlawed that kind of control. Even plain old washing lines can be erected in HOA areas because they are classed as a renewable energy device.

If backward places like FL have these protections from HOAs, I'm sure saner places will have too.

Our solar hot water system went up last summer, after we replaced the roof. It works great, water is far hotter than it would be from the old electric system, and we've only need to use the backup electric heating on about 8 or 9 occasions over the winter.

Our washing line, cunningly erected over the pool also works a treat.

Re:Curious...

[uncqual]

15K added upfront to the cost of a California home if virtually nothing.

Huh? It's $15K whether the house is $150K or $1.5M. Indeed, due to the the limit on mortgage interest deduction for Federal tax purposes ($1M?), the purchaser of the $150K home would likely get an additional tax break on the $15K solar energy equipment cost which the $1.5M homeowner might well lose out on.

Is a $15K home theater system any cheaper for someone with a $1.5M house than a $150K house? It's about ROI in both cases and the solar equation is no different.

Re:Curious...

[MindStalker]

Because for average Joe, its not about total payout, its about monthly cost. That $15K will run you maybe $100 a month extra for a 30 year loan. Depending upon where you live you will save much more than $100 a month in electricity.

Re:Curious...

[uncqual]

Yep - but it's $100/month regardless of the cost of the house due to regional variations (well, perhaps effectively less to the owner of the $150k home due to the mortgage deduction issue in my post above). I stated no opinion on if this particular $15K investment had a better risk adjusted ROI than an available alternative investment (I've not researched this so have no opinion on this point).

BTW, in the high price area, it's likely to cost more to install the system (due to labor costs and increased contractor overhead costs) than in a low cost area which could make it less attractive for the $1.5M home - although it's possible that this particular upgrade may have more qualified installation contractors in high cost areas than lower cost areas resulting in more efficient installs and/or more competition which could offset the other increased costs.

They're the ones...

[Anonymous Coward]

The governor also asked the PUC to work with the state's three investor-owned utilities to come up with "a properly designed rate structure" that doesn't penalize solar owners, Maile said.

The utility guys are the ones who lobbied for the unfair law in the first place! Do the folks of CA actually think the utilities are going to fix it?

"The fact that some customers may find themselves paying higher electricity bills if they decide to install solar ... is unfortunate and indeed perverse," California PUC President Michael R. Peevey said in a recent letter to legislators.

Translation: "We don't give a shit. We got the law we want and we're getting the money we want one way or another. Ha ha!"

Re:They're the ones...

[NeutronCowboy]

The law was designed by the utility guys? Why am I not surprised that the math doesn't work out? To some extent, I'm willing to go off-grid just to spite those fuckers. The electric utilities in California have been some of the most despicable monopolies I've seen... they've done everything they could to milk everyone for more money, including buying absurdly beneficial legislation (like the deregulation that was only in name), shutting down power plants during the highest load times to be able to justify rate hikes and just generally not giving a flying fuck about the people subjected to their monopoly.

If I can afford the increased cost of going off-grid, I will. Make magazine has a how-to for making a wind-powered generator, solar panels are available, and the only thing that's missing is a home fuel cell to provide a steady supply of power when all else fails. It's not cheap, but I'll be ecstatic when I'll be able to cut that stupid line to PGE. This is not a question of if, but of when. I hope that that won't be illegal when I'll be able to do it.

Google as the new Power corp

[HalifaxRage]

So what percentage of total power generation is now attributed to the Google campus?

Re:Google as the new Power corp

[Anonymous Coward]

If you're not feeding electricity back into the grid (which is a good thing BTW) then why should they force you to take a different rate? It seems that legislation was done in favor of the utility companies.

Yes I'm still waiting for cheap efficient cells also ... we're not quite there yet. When that happens the utilities are pretty much SOL.

Re:Google as the new Power corp

[misleb]

Yes I'm still waiting for cheap efficient cells also ... we're not quite there yet. When that happens the utilities are pretty much SOL.

I think they'd have to be pretty darn cheap AND efficient to make utilities really that scared. I mean EXTREMELY cheap and efficient... like by an order of magnitude compared to now. It also depends on the area. In many places outside of CA, power is actually pretty cheap and there just isn't that much solar energy to go around.

-matthew

The math will never come out with current panels

[arivanov]

The math with current photovoltaics will not come out in favour until the fossil fuel rises by a factor of at least 10 times. Does not matter what, how, who, where. They are simply too expensive to provide a reasonable ROI. They also have a very high environmental cost to produce so people who buy them are not doing a lot of good to the environment. Photovoltaics are a gimmick, similar to the hybrid cars which allow metrosexuals and hollywood stars to show off some fake green credentials.

The only working nowdays solar tech for electricity is this: http://news.bbc.co.uk/1/hi/sci/tech/6616651.stm. The tech is originally french (they have been running a pilot plant like this near Marseiles since the mid-70es). For the numbers quoted in the article the performance is quite impressive. 22MW is a small plant, most of them have per-KW cost higher than the normal electricity cost anyway. It is also first of a kind, so cost is inevitably higher like for any new tech. If this is industrialised it should be able to produce electricity at nearly normal costs in any place where you have sun and water to use as a coolant. Plenty of empty land near the coasts around the world to use for this.

Power Productions

[Applekid]

I Am Not A Powerplant Engineer, so...

Does it really cost more to provide energy at certain hours than others? Or is this just a case of the utility company fiddling with the rates in the only way they can to bilk more money out of everyone?

Re:Power Productions

[faloi]

I'm not one either... But it seems sort of logical. There's more power being used, more stress on their systems, likely a need for better monitoring which requires more people. Or at least that's how I see it, someone that really knows what's happening might be able to make it make more sense. It's probably a good idea for people who see most of their big usage in non-peak hours (nightclubs, maybe), but pretty much a raw deal for everybody else.

Re:Power Productions

[Gilmoure]

Summertime demand is higher as more AC units run. At night time, AC doesn't have to work as hard.

Had rolling blackouts at the college I worked at in summer of 99. Servers up! Servers down! Found out how well our data center UPS worked. Tits up on the first day.

Re:Power Productions

[Anonymous Coward]

Supply and demand. They likely needed to institute higher prices at what was normally peak demand to try to get customers to reduce their usage. It's alot cheaper and easier than building X new powerplants to cover the load.

Re:Power Productions

[Anonymous Coward]

It kind of costs more to produce more based on peak demand. Peak demand just happens to occur during the daylight hours when everyone is at work. The reason is that power companies have a baseline generating capacity. To cover peak demand, they fire up additional generating sources, often natural gas or oil fired plants that are only run when demand peaks because they are higher cost generating source.

Re:Power Productions

[sgauss]

Yes. Electricity usage is higher at predictable times of the day, i.e. when people are working and using a lot of electricity for air conditioning. This forces the power company to use less efficient power plants, or buy electricity from other regions to meet the peak demand.

Re:Power Productions

[Anonymous Coward]

Does it really cost more to provide energy at certain hours than others?

Well, yes.

In the old days, the utility would blend all these rates together, because it would be too expensive to fit every home with a smart meter that could track usage by time of day. These days, many utilities do time-of-day metering.

Most people tend to use electricity at certain times of the day. For example, you don't tend to use much when you are sleeping.

If you run a utility, you need to get power to supply to your customers. Since power demand varies a great deal, your utility might not own enough generating capacity to meet demand during peak times. So you buy electricity from someone else.

Now suppose you are that someone else, who owns a power generating plant. Almost no one wants to buy your electricity during the middle of the night, but lots of people want to buy it in the afternoon. Would you charge more during the afternoon than the middle of the night? Of course you would.

Re:Power Productions

[Anonymous Coward]

The other thing is to encourage shifting load to times when there is less demand. Air condition your house during the day, do the washing, etc. at night.

Re:Power Productions

[MBCook]

A power plant costs roughly the same amount whether it's 9:00 AM or 9:00 PM. You probably have to pay people on night shift more, but that's negligible in the end.

This is just supply and demand. They can get more more, and encourage less demand by doing this. Because the difference between peak and lows is so large, they may have to bring an additional power plant online (running 3 plants is more expensive than 2) or buy the electricity from another provider (more expensive than making it yourself). Plus in low demand you could turn off part of a plant (for example some of the turbines/coal furnaces, thus saving fuel and labor).

There is a good reason for it to happen. The actual variance in rates may be bigger than necessary, but it makes sense.

Re:Power Productions

[IvyKing]

Does it really cost more to provide energy at certain hours than others? Or is this just a case of the utility company fiddling with the rates in the only way they can to bilk more money out of everyone?

It isn't so much that the incremental cost of producing the power is higher at peak times as it is the cost of capital for an asset that's used less than 10% of the time. What makes life a bit worse is Calif's big FU attempt at deregulation where the utilities were forced to sell off their generation to companies that charge even higher rates during peak times than what the utilities would have done otherwise.

The first step that Calif should have taken in deregulation was to phase in time of day power for everyone over a ten year period. This would also make the economics of solar a lot better as the peak output of solar panels occurs during peak load times.

Re:Power Productions

[Anonymous Coward]

somehow i think more power would be used in the evenings/night

Re:Power Productions

[tzhuge]

I'm not a power engineer either but I am an EE. My understanding is that there just isn't a good way to store massive amounts of power. (They use some tricks like pumping water back up to the top of a dam.) So the entire power grid is a massive control problem. They have systems that are doing calculations in real-time and generating units, sources of capacitance and inductance have to be brought online and taken off-line as needed. Hydro, nuclear and large coal burning plants supply the base-load (those take weeks to take on/off line) and they have smaller (probably less efficient) generating units to take care of peak demand. I seem to remember hearing about some utility resorting to portable diesel generators to meet air conditioner load during the summer. I assume these peak load generating units cost more while running. They can also buy electricity off the grid.. which I would assume costs more as well.

Re:Power Productions

[thousandinone]

During peak times, more current is being drawn, putting more wear and tear on the equipment. This in turn requires more staffing during peak times for preventive and reactionary maintenance. The higher peak charges are likely to be mostly attributed to wages and maintenance costs.

Re:Power Productions

[maxume]

It also effectively reduces peak demand(because if it saves somebody money to move usage, they generally will do so) and saves them on capital investment. I'll bet there is a decent negative correlation between operating costs and plant size, and any plant they don't keep running all the time is naturally going to be more expensive to own(unless they are impossibly stupid).

Re:Power Productions

[petermgreen]

Does it really cost more to provide energy at certain hours than others?
sort of

the big coal and nuke plants plants have a low running cost per unit but have high upfront costs and/or aren't good at ramping up and down (this is particularlly true of nuclear) so they get run at full or nearly full power 24/7.

most renewables generate when nature lets them. If your lucky thats at the same time the demand peaks and thats great. If not then the renewables become even worse than the coal and nuke plants above.

something has to cover the peaks in demand (since customers demand electricity will be availible when they want it) there are a few options for this, all are either in limited supply or result in a higher cost per unit than for base load (large coal and nuke plants that run 24/7).

dam based hydro: This one is very effective (generally with hydro you get a limited supply of water but a lot of flexibility in when you spend that supply) and not too expensive but there are a limited number of sites that are both techincally and polictically (resistance effects of flooding land and disrupting the river) viable and most such sites in the west have already been developed.

pumped storage: essentially a variant of the above but you pump the water back up when power is cheap. The downside is the cost per unit is high as you have to pay for the power used to pump the water up (which is more than the power generated) as well as all the other costs of running a hydro plant AND a pumping station.

battery storage: cost of the batteries is a killer, loss is a problem too.

fossil fuel (often natural gas) generation: cost per unit is higher than for base load both because they tend to use more expensive fuel than the base load plants and because assets are sitting idle.

Re:Power Productions

[illegalcortex]

This forces the power company to use less efficient power plants, or buy electricity from other regions to meet the peak demand.

And this one can be a real killer, as the seller knows they have the buyer by the balls. They often pay a pretty penny for that extra power.

Re:Power Productions

[SQLGuru]

I used to work for a power company (in I/T, not operations), so I have some level of credibility for this statement:

The daytime is actually higher due to businesses. If you go in a store, every light is on, the large A/C units are running, servers, desktops, etc. After 6, things start to get shut down. After 9, even the lights of a store are put in "night mode" so that only a few security lights are on.

The amount of electricity used by the typical homeowner at night is not that much. For example, at my house, most of the house is dark at around 10 (kids in bed, etc.) with just my wife and I in our bedroom watching TV with maybe a lamp on low (or dark, depends). It's cooler at night, so the A/C doesn't run as hard. All of the other load is constant anyway (fridge, computers, etc.).

Layne

Re:Power Productions

[SQLGuru]

Actually, you are forgetting the fuel to run that plant. If there is higher need, you have higher fuel costs. Also, the amount of staff you need to run 3 of 5 boilers is different from having to run 5 of 5 boilers or 1 of 5 boilers. Demand shapes the cost.

A lot of power companies still have some sort of regulated component to their profit. If it was solely supply and demand, you would find that it wouldn't make much sense to do it because their profit would be capped anyway.....no matter when you used the power.

Layne

Re:Power Productions

[mrand]

somehow i think more power would be used in the evenings/night ... because, as everyone knows, the sun shines hottest at night.

No wonder you posted as an AC.

      Marc

Re:Power Productions

[indifferent children]

likely a need for better monitoring which requires more people

An even bigger reason for high-costs during peak usage is that your utility has to buy power from the interstate grid and/or third-party 'merchant plants' when their own generating capacity is insufficient. That can be very expensive.

Re:Power Productions

[UbuntuDupe]

The others explained the reasons for the *change* in rates based on time of use, but I've really got to comment on the absolute level of the price. 29-35 cents per kwh? For reference, does anyone remember in the Enron/California Energy scandal about how some guy was caught on tape bragging about how he was gonna (paraphrasing) shove overpriced electricity down grandma's throat at $250 per MWh? That's 25 cents per kwh. And the dude obviously considered that an extremely high price.

Incidentally, I checked the plans my provider (TXU) offers. None has variable rate pricing, where I'd pay less after six and more during the day. If it did, I'd take it, since only my refrigerator and a few clocks are running during the daytime.

Re:Power Productions

[spickus]

Why do they have to add reactance?

Re:Power Productions

[tzhuge]

If my memory is right, it's to compensate for reactive loading on the grid, in order to maintain power quality.

Re:Power Productions

[jtgreg]

We signed up for time-of-use rates when we lived in the Bay Area, but the financial incentives seemed out of whack. You get a slight discount for using off-peak power, and get large surcharges for using peak power. (Why does my peak power cost more than the normal users when I am trying to help them out?)

We had a pool so we were a heavy user, but a whole month of carefully shifting your usage to off-peak was wiped out by one afternoon pool party. The only incentive for the inconvenience was hoping that you reduced the utility's afternoon peak demand. It was also counter-productive for using the pool's solar heater.

It seems that the utility didn't really want this program to work, at least for pool owners (a large group in CA), and were just fulfilling a state mandate to offer time-of-use rates.

Industry Lobbying

[Skidge]

The article doesn't mention it, so why was this time of use rate requirement added to the law? Was it a result of energy industry lobbying? Did the state legislature just not do the math?

but with things in flux

[stoolpigeon]

you'd want some flexibility in your system
 
wisdom for the ages.

Re:but with things in flux

[mdsolar]

Thanks! That was a bit of a pitch for renting.

Alternative power storage

[simm1701]

You can save more money if you store energy during the cheap period of the night.

There is a rather interesting alternative to batteries as power storage - unfortunately its a little expensive on setup costs.

Compressed air storage. The same thing you hear is powering those new cars, its also used in a couple of large sclae power stations world wide (one in the US and one in Germany iirc)

The idea is you store air in high presure cylynders, 6000psi 540 cubic feet of air ones are quite good - these are standard and used for filling smaller cylynders (eg for diving) normally. The advantage is as these type of things go they are relatively commodity while being very high pressure. One of these will store about 1Kwh and is about 3' tall and 1' diameter. Lets say you are going to need about 16kWh during the day for lighting and electricy (you won't need any for air con, we'll get to that)

During the night you compress air into these empty tanks (you calibrate the day use to make sure they are empty by the end of the day) Compressing the air generates heat, so you use water to cool this, you should be able to extract enough heat in the water to fill your average hot water tank 4 or 5 times. This can be used for normal hot water, heating a swimming pool or in colder places/times of year for heating (under floor ideally). Compression is about 80% efficient in terms of energy in to potential electricy generating cpacity of the stored air. However factor in the heat you have stored for hot water and you are doing better than 100% - assuming you do use that hot water.

During the day the compressed air is used to run a gas turbine, you should be able to get about 80% efficency again and be able to run a 2-3 kW generator, however the "waste product" is nice cold air - hence no need for an airconditioning system, you just pump this air around your house.

So overall:

During the night you use 24kWh of electricy at cheap rates to store air into 20 of these tanks.
You also end up with about 24kWh of waste heat used to heat your hot water for free - thats definitely your normal hot water use covered, under floor central heating and probably atleast part of your swimming pool if you have one.
During the day you get about 16kWh of useful electricy, plus you get all that nice cold air to cool your house down (about 10,000 cubic feet at a very very low temperature)

Not only do you get a net out of nearly double what you put in, you are also paying less for what you put in that you would if you used that power normally during the day, add a few solar panels and you are laughing.

The draw back?

Cost, you are looking at atleast $40k to install this type of system, plus its not exactly off the self - all the individual components are but you can't just buy it as a package, be nice if it was though!!

Re:Alternative power storage

[rohar]

Diagram of Compressed Air Storage Idea

Re:Alternative power storage

[Moofie]

"You can save more money if you store energy during the cheap period of the night."

Genius. Why didn't I think of that! Use your solar panels to charge your batteries...at night!

"However factor in the heat you have stored for hot water and you are doing better than 100% "

*eyebrow* I'd like to see your work there, cowboy. Most of the time, thermodynamic processes don't give above-unity efficiency. And by "most", I mean "absolutely all".

Re:Alternative power storage

[OwnedByTwoCats]

540 cubic feet of air ones are quite good .... One of these will store about 1Kwh and is about 3' tall and 1' diameter.

Ummm, 3' tall and 1' diameter is (scribbling furiously) less than 3 cubic feet. 6 feet tall and 3.4 feet in diameter is 54 cubic feet, so you'd need 10 of them...

24 KWh of electricity. Since you're efficiency is 64%, so you're using 1.64 KWh at 20 cents per to replace 1 KWh at 30 cents per. The net is more like 3 cents/KWh. * 24 KWh, means you save 72 cents per day * 365 days in a year, and you're saving $262.80 per year. The $40,000 cost, invested in a savings account paying 2% per year generates $800 per year.

I'll let someone else calculate how much hot water and cold air the "waste" sides of running this system would actually generate.

Re:Alternative power storage

[simm1701]

Try reading the post ;)

Store power during the cheap period of the night (ie buying it from the grid during the night, off peak tariff, economy 7 whatever you want to call it)

As for the efficeincy you are not beating 100% for the entire system, thereby obeying the laws of thermo dynamics, but since you are storing 20kWh and have 24KWh in waste heat to use then when you measure energy in that you paid for against energy out that you want, you beat 100% (I think this is termed the economic effieciency but I could be wrong on terminology)

Where does that heat come from? From the air - if you compress air and want to keep it at the same temperature you are going to have to take a lot of energy out - see the combined gas law (and Boyles law + Charles law). this has to have a side effect right? Of cours e- the air is going to be cold when you decompress it. But in our case thats useful - free air conditioning.

1 lot of energy in, useful effect out in 3 different ways (as I said actually reading the original post is such a novel idea)

Re:Alternative power storage

[simm1701]

Depend son the area - UK economy 7 tariff is 3.5p/unit off peak and 11p/unit peak - atleast where I am.

Also that 540 cubic feet is how much air at standard presure and temperature (ie room temp and normal air pressure) it will hold when compressed to 6000psi at standard temerature. don't ask me why its rated like that but thats what the tank specs get listed as.

Re:Alternative power storage

[Moofie]

Oh, I read the post. You entered a discussion on solar energy, and then took a left turn into not-solar-energy without specifying such. Yes, I understood your point. No, you were not clear.

So, you're saying that your 24 kwh is going to run a compressor, that will put air into perfectly insulated tanks (I'd really like to see your arithmetic here). OK, fine. Assuming you do so reversibly, you'll get out exactly as much energy as you put in. No, you can't do so reversibly.

But, after you pressurize the tanks, you want to cool them with water. Ideal Gas Law says that if you decrease temperature, you decrease pressure. Now you've got way, WAY less energy in your tanks to reverse-run your compressor (which, you might note, will be less efficient than a compressor optimized to compress).

So, yeah, I still want to see your work, because from where I'm standing, it looks like bullshit.

"(as I said actually reading the original post is such a novel idea)"

Would have been better if you were actually knowing what you were talking about, but OK.

Re:Alternative power storage

[Anonymous Coward]

However factor in the heat you have stored for hot water and you are doing better than 100% -

OK, you lost me right there. You CANNOT do better than 100%. It's simply impossible. Better than 100% would mean that you gain energy - that you magically create it out of nowhere. It would mean that you've discovered perpetual motion.

It means that your whole post is now suspect, and should be modded down.

Re:Alternative power storage

[mcarp]

Well, I'm proud of all the /.ers who caught the wackiness in the electric universe artical a bit back, but where in the ACHE did this nut come from? IANARS but more than 100% is automatic wacko. What 4 lunitics modded this up to 5? It should have a -1 by now. If you dont already know that compressing air costs a LOT more than simply charging batteries, you need getting shot. Heat transfer is not an effecient process. The numbers in this comment are completely made up. If you use 24kWh to charge attempt charging these tanks you can not possibly get 24kWh of waste heat available AND charge any tanks. 24 - 24 = 0 as far as I know from checking last. I could go on and on about this comment but isnt it already obviously a complete mess? As pressure rises in a tank it takes ever more energy to squeeze that next little bit in there. When will people learn that adding steps in an energy exchange process is always a loss?

electrolysis on water for hydrogen: less energy storage than batteries.
electricity to compressing air: less energy storage than batteries.
electricity excites Pd/D mesh to 'fusion' to heat to er... I mean background noise

Well, you get the point.

Re:Alternative power storage

[zenslug]

Thanks for the info.

Re:Alternative power storage

[SuperBanana]

You can save more money if you store energy during the cheap period of the night.

[Long, complex, convoluted, yet still oversimplified air-compression-energy-storage system snipped]

Don't bother. Cut your energy usage as much as possible during peak rates, so that you put energy back into the grid from your solar/wind/hydro when you'll earn the most money. Same effect, much, much simpler. Your "plan" made some pretty serious assumptions about scale, safety, and complexity. The devil is in the details.

Do your laundry at night, and if you want something to tinker with, use a thermal reservoir to heat or cool fluid which can be circulated through your central air system, if you have one. The cold or warm water can be used not to keep the house comfortable during the day (when nobody is around), but for right before you get home. It's amazing how much heat can be put into water...1000cc's of water can store ~4kJ from just ONE degree Celcius temperature change. A 55 gallon drum of water has a potential of 832kJ per degree Celcius. Now, let's say you raise its temperature from 20C (room temp) to 60C; you're looking at 33MJ, or (god, I hope I did all my unit conversions and math correctly), 9kWhrs. Naturally there will be some losses even if you use decent insulation, but...

Re:Alternative power storage

[illegalcortex]

What's the point of this? At $40k, that's $333/month over 10 years. Even at 30 years, it's $111/month. And you're running a big risk of either just not getting that $40k back on house resale, or actually getting a LOWER price because of it. Most people wouldn't be gung ho about such a setup, and restricting your pool of buyers will most likely cause the a price hit.

So, even living there, it's an extra $111 a month. What size house do you have to have for that to really make sense on your power bills? Is it supposed to be "greener"? As I see it, you'd be using more power than you would normally, especially during the winter where all that cold air won't do you any good. I've heard a lot of "amateur expert" talk about how power plants work and such, but will increasing their off-peak load proportionally increase the amount of fossil fuel they burn (if they are a fossil fuel plant)?

It sounds neat, in theory, but bad in reality.

Re:Alternative power storage

[maxume]

You aren't doing better than 100% in any thermodynamic sense.

It appears you mean that by capturing waste heat and using the waste air for cooling that it becomes economical to use the system instead of relying on the grid. This may be true, but the electric company will quickly get rid of differential rates(or start doing it themselves) if it catches on.

Re:Alternative power storage

[simm1701]

No you pull the energy out of the heat in the air.

Check it - take 10800 cubic feet of air at stp, comrpess it to 6000psi - keeping it at the same pressure cool it with water, now figure out how many joules has gone into that water and how much that water temperature has now gone up.

You still have the compressed air in the tank - which gives you both cool air on demand and its stored potential energy (ie the compressed air will drive a turbine)

Re:Alternative power storage

[simm1701]

Yes its an over simplification - its a post on slashdot.

The tollerance specs on the equipment required runs to several pages each, tanks, turbine generator, not to mention water and air pumps plus the control systems you would need.

You're right though - the best place to "store" energy is in the grid -especially if you can get a decent sell back price from them.

As you say water storage for temerpature is also pretty good (but then thats the other side of this system for home use, you store the heat generated by compression into water)

Net the air compression storage by itself is worse than batteries - you dont have the economies of scale large power plants that use this do. It becomes useful in the side effects of hot water and cold air.

But personally I'd rather go for a wind turbine, a ground source heat pump and cutting down usage where I can (I'm in the uk so solar isn't too much use)

Re:Alternative power storage

[simm1701]

Exactly, you cannot beat the laws of thermodynamics, but you can in effect steal energy from elsewhere, same as with heat pumps

The problem with any peak time storage based system (which the discussion got to by power companies forcing people onto the peak/offpeak rates) is if it gets suffiently viable to store power when its cheap everyone will start doing it and then the peak/off peak will average out... however that averaging out on the whole would be a good thing, but economically isn't really going to happen.

Re:Alternative power storage

[simm1701]

my current electricity bill for an average house in the uk is 1200 pounds per year - and I don't have air con - thats 2400usd btw

Thats way above average as where I am located I'm stuck with storage heaters.

Something like this could half my electric bill plus provide air con (which I don't currently have) and would provide more hot water than I currently use.

Yet it would still take 10 years atleast to break even - as I said the problem is the cost.

It wouldn't help if everyone increased their off peak usage, but electric companies are keen to make sure their off peak usage atleast uses all the power nuclear plants can make - sicne these are effectively always on it makes sense to get the most use from the possible. For the uk the provide about 20% of total generating capacity (or atleast did in the late 90's the last time I had access to detailed figures, I'm sure you could find more current info online if you are inclined to look)

Re:Alternative power storage

[maxume]

This system is nothing like a heat pump. There is no energy extracted from the environment here, it is entirely self contained, there is no amplification of the grid input.

If space is available, a ground source heat pump(which are getting called geothermal furnaces and the like) is going to be way more cost effective and provide energy on demand.

Re:Alternative power storage

[simm1701]

No the ideal gas law says that in a closed system if you increase the pressure you will increase the temperature and via verser - there is nothing to stop you taking the energy from that energy increase and moving it elsewhere. (if what you were saying were true freezers, fridges, heat pumps or air conditioning systems would not function)

You don't cools the tanks by the way, you cool the air just after it leaves the compressor before it reaches the tanks - its still at high pressure at this point, cooling it doesn't lower the pressure.

You do not need to insulate the air tanks - the only requirment is the air going into the tanks is at a temperature within the tanks tollerance (hence cooling it while its still at pressure)

A lot of this is counter intuitive I will admit - but thats because you are trying to ignore the whole system and think only of the electic in, the compressor, the tank, and then decompressing through the turbine. The energy within the air is the other component within the system (and the fact when the air is decompressed its much cooler, ie has less energy)

Feel free to do the math, compress 10800 cubic feet of air to 6000psi, find out what temperature it now is, figure out the specific heat capacity, find out what water is heated by using the water to cool this, find out how much cooling potential you have on release, then add in the 64% (ish) efficiency you have on the actual electric storage to generation cycle, then take into account 3 times price difference of peak to off peak prices (which is what I currently pay, see economy 7 tariff on scottish power for regions in the south of england if you want proof of that)

Now the hard bit - putting that system together, safely with the right automatic controls as someone else here pointed out - hence as in my oringal post the $40k price tag (and thats being optimistic)

Oh and the discussion was on solar energy and its viability in a peak/off opeak pricing system - my comment was on the latter

Re:Alternative power storage

[Moofie]

"its still at high pressure at this point, cooling it doesn't lower the pressure."

Horse puckey. What you describe is an intercooler, and is common in turbocharged engines. It is NOT, repeat, NOT, a source of free energy.

"A lot of this is counter intuitive I will admit"

If by "counter intuitive" you mean "violates the laws of thermodynamics", then yes, I'd say it's counter intuitive.

Re:Alternative power storage

[simm1701]

It takes the energy from the air - same as an air source heat pump (which are available as commercial heating solutions), its not as concentrated as in the ground but its there go read up on them

Re:Alternative power storage

[DeadCatX2]

Wow, you're not only ignorant, but you're a prick too!

You entered a discussion on solar energy, and then took a left turn into not-solar-energy without specifying such.

Uh...wrong? The beginning of the post stated "compressed air storage". The only mention of solar panels is at the very end, "add a few solar panels and you are laughing"

But, after you pressurize the tanks, you want to cool them with water. Ideal Gas Law says that if you decrease temperature, you decrease pressure.

The tank itself keeps the volume constant. The water cooling is meant to keep the temperature constant (pressure up, temperature up, right?). Add moles of gas, get an increase in pressure. I don't see what part of the Ideal Gas Law is being violated.

Re:Alternative power storage

[Rob the Bold]

No you pull the energy out of the heat in the air.

Something is definitely being pulled out of something.

Check it - take 10800 cubic feet of air at stp, comrpess it to 6000psi - keeping it at the same pressure cool it with water, now figure out how many joules has gone into that water and how much that water temperature has now gone up.

How, pray, do you intend to remove the heat and keep it at the same pressure? Consider the ideal gas law:

pV=nRT

If you reduce the temperature (T) and keep the pressure (p) constant, you must do one or more of the following:

Increase the number of mols of gas (n) - i.e. adding more gas (by using more energy),

Increase the gas constant (R) - i.e. changing the laws of physics,

Reduce the volume (V) - i.e. expending the stored energy.

So, unless you can change the law of physics, you're pretty much stuck.

Re:Alternative power storage

[simm1701]

The "waste" heat is what you get from the air as you compress it - not from inefficiencies of the compressor, see Charle's law. You get maybe 4kWh of waste on the compressor itself (and you need to make sure it does not over heat) and the air itself is what gives you the rest, it needs to be cool enough by the time it reaches the tanks not to damage them or the valves.

The pure energy storage of this type of system? 64% efficent at best (assuming 80% efficent compressor and 80% efficient turbine/generator system - actually quite realistic for good quality systems)

You gain on the heat you pull out of the air (see air source heat pump), you also gain on cold air that replaces the power you would need for air conidtioning, so in value to you its a lot mor than just the power storage capability - as said before downside = cost + implementation complexity

See the diagram someone else linked for how its done on large scale power stations

Re:Alternative power storage

[Moofie]

"I don't see what part of the Ideal Gas Law is being violated."

I didn't say it was being violated. I said that in order to not violate it, you decrease temperature, T, you decrease pressure, P, because the ideal gas law states that pressure and temperature are directly proportional in a fixed volume.

PV=nRT

I might be being a little snippy (I was actually going for 'jocular', but I may well have missed), but I'm pretty confident in the thermodynamics. By all means, illustrate my errors, and I'll be glad to eat crow.

Re:Alternative power storage

[Anonymous Coward]

But, after you pressurize the tanks, you want to cool them with water

Cool them WHILE pressurizing them. For a tank with a fixed maximum PSI, this permits the storage of more air (due to the reduced pressure). Heating the tank with sunlight when you're draining the tank and using the energy helps towards keeping the pressure up.

Greater than 100% energy efficiency is obviously impossible, but in terms of dollars, it most certainly can be done, especially if off-peak electricity is much cheaper than peak electricity charges. Heat inefficiency from the pump can be used (water heater) rather than just wasted, and peak energy usage is reduced both in terms of recreating some of the off-peak electricity by running a turbine (better designed than running a compressor "in reverse"), plus decompression-cooled air to offset air conditioning needs and reduce electricity demand.

Re:Alternative power storage

[simm1701]

There is no such thing as free energy. However air has quite a bit of energy - about 1J/gK at stp

Lowering the pressure of a gas will lower its temperature - this is how a lot of cryogenic plants work, using expansion of compressed gas as a cooling machanism (compress, it heats up, cool to room temp while under same pressure then decompress, and voila the temeprature has dropped)

Take a piston, compress the gas inside it to 6000psi, its going to get hotter.

Leave it to cool back to romm temperature but without retracting the piston (lets assume for the moment there is no leakage or air in or out - thats another matter and I'm trying to keep this simple for you) - keep it at that pressure, the gas is not going to go to a lower pressure, it can't it has no where to go.

If you think it will go to a lower pressure I'd love to hear your explanation - I could really use a good laugh!!

Re:Alternative power storage

[DeadCatX2]

I said that in order to not violate it, you decrease temperature, T, you decrease pressure, P, because the ideal gas law states that pressure and temperature are directly proportional in a fixed volume for a fixed amount of gas.

There, fixed that for ya.

PV = nRT, yes, thank you. T goes down, n goes up, P stays the same.

Re:Alternative power storage

[maxume]

The pumping waste is going to slightly exceed the energy recovered from the hot compressed air.

Heat pumps(most of them...) work by exposing different parts of the vapor compression cycle to environments that are separated by a barrier. The system you described does not do this.

Re:Alternative power storage

[Moofie]

"keep it at that pressure, the gas is not going to go to a lower pressure, it can't it has no where to go."

You very seriously need to read a text on thermodynamics. You are completely incorrect. The pressure DOES decrease, because (assuming we're dealing with an ideal gas, which is a pretty good assumption unless you're doing something rather exotic), the pressure in the cylinder is proportional to the product of temperature and volume. PV=nRT. That's the Ideal Gas Law, and it's rather well-regarded in the study of thermodynamics. Since you're assuming constant volume in the cooling process, pressure is directly proportional to temperature.

You're assuming that pressure comes from the physical proximity of gas molecules to one another, and therefore, the pressure will be constant regardless of the energy state of those molecules. That is a fundamental misunderstanding of the physics inside that cylinder.

Re:Alternative power storage

[DeadCatX2]

IANARS but more than 100% is automatic wacko.

I guess you missed the part where this isn't about 100% energy efficiency, but about taking advantage of the cheaper cost of electricity during off-peak hours to get better than 100% efficiency in terms of the dollar.

Re:Alternative power storage

[Moofie]

Hold on. We're talking about air in pressure vessel. n is constant.

Yes, clearly, if you hold P constant, and T goes down, you must add more gas.

Re:Alternative power storage

[Rob the Bold]

PV = nRT, yes, thank you. T goes down, n goes up, P stays the same.

When you put more gas in, you expend energy doing it. If you then cool that gas in a rigid container, the pressure will decrease. If you put more gas in to bring the pressure back up, then you expend more energy doing that. And so on . . . You won't get free energy.

Re:Alternative power storage

[DeadCatX2]

If you cool the gas, the pressure goes down, and you can jam more gas into the same volume while still meeting the pressure spec of the tank. This effectively increases the storage capacity of the tank, allowing you to add more compressed gas (up to the pressure limit of your tank).

I think the trick is to compress the gas while holding volume and quantity fixed, resulting in an increase in temperature. Then, pull the heat from the gas, cooling it and causing the temperature to go down. Pressure goes down now, too, and this should make it easier to store the air in the tank.

Re:Alternative power storage

[DeadCatX2]

It's not about free energy! Yes, you expend more energy putting more gas into the tank, but you will recoup some/most of that energy when it comes time for it to be released.

Not 100% energy efficient, but more than 100% dollar efficient. If off-peak electricity is one-third of the cost of peak electricity, and your system is overall 50% efficient at converting off-peak electricity to peak electricity, you have more than 100% dollar efficiency.

Re:Alternative power storage

[DerekLyons]

Not only do you get a net out of nearly double what you put in, you are also paying less for what you put in that you would if you used that power normally during the day, add a few solar panels and you are laughing.

So claims your handwaving calculations (backed up by a healthy dose of unsupported assumptions). Do you have real numbers and actual equipment?

Re:Alternative power storage

[illegalcortex]

Do you have a very large house? Or is your house very old? Or is it both? Is the heating gas or electric? I'm just curious. I live in fairly old house (for the US) in a cool climate (though probably comparable to just about anywhere in the UK), and mine is around 1000 USD a year. Granted, it's gas heated, including the water, and that runs me even more a year than the electric. But I do run the A/C a good bit in the summer, and that gas is paying to sometimes heat the house during prolonged double-digit subzero weather. Total square footage is around 2000, including basement. Must be all those CFLs. ;)

Actually, I bring this up to ask if you've done everything you can to make your house energy efficient. I have double-glazed vinyl windows on pretty much every window that wasn't a non-standard size. And then there are the CFLs. I wonder how much you could cut down on your bill with these kinds of improvements.

Also, I'm a little puzzled by your comment about taking 10 years to break even. I think 10 years is unreasonably optimistic. If you are paying $2400/year, that would be $200/month. This setup was quoted at around $40K. Even if it halves your electric bill, that only saves you $100 a month. At $100 a month, it would take 33 years JUST to break even. And that's not even factoring in how much money you could have made with $40K over 33 years by investing it. Even if the $40K estimate is double what it would be for your home, that still means it's over 16 years. This also assumes it won't come with increased maintenance costs.

If such a system could save you $100/month at an initial outlay of $10K, then it might become reasonable.

Re:Alternative power storage

[DeadCatX2]

When the tank has no pressure, there are x moles of gas in it. As you start adding more gas to the tank (you know, storing the compressed air) there's now y moles of gas in it, where y > x. In order to fit more moles of gas into the tank, the gas is cooled, which results in the gas exerting less pressure, and now you can fit more gas into the storage tank without violating the pressure spec on the tank.

Again, we are not pulling energy out of nowhere. There's a lot of translating energy, though. Taking cheap electrical energy to store energy and suck heat off in order to allow us to store more air, and use that excess heat where we want it. Take the stored energy and use it when electrical energy isn't so cheap, and it just so happens that the decompression sucks heat out of the house.

Re:Alternative power storage

[Crispy Critters]

"The problem with any peak time storage based system (which the discussion got to by power companies forcing people onto the peak/offpeak rates) is if it gets sufficiently viable to store power when its cheap everyone will start doing it and then the peak/off peak will average out"

That is not a problem, that is a good thing. During heavy use times in CA, the peak usage during the day is like twice the minimum usage at night. This means plants are starting up and shutting down every day to match the usage pattern, and 50% more power plants are needed than if the usage were even. Constant usage rate should result in cheaper power for everyone.

It would be great if appliances were smarter, and instead of a brownout we could have everybody's air conditioning and hot water heater turn themselves to a lower setting when the system is overloaded. I don't see that this could happen in our lifetimes.

Arguing with the armchair physicists on slashdot is about as productive arguing with armchair physicists on usenet was 15 years ago. I think the claim that the efficiency was over 100% is what set them off. It was too much to hope that they would think for 5 minutes to understand what you are saying.

It is clear that your system works best when the daytime temperature outside is warmer then desirable room temperature. I am not sure what happens if the outside temperature is 10 degrees F. How does the efficiency of the turbines depend on the discharge environment? (You don't want to pump cold air into a heated house in the winter, so the turbines will have to discharge into 10 F.) Anyway, the cold air output provides no benefit, so you lose somewhat in your "efficiency" there. Maybe the insolation in winter is so low that it doesn't matter.

Re:Alternative power storage

[woztheproblem]

Yeah, but since the gas is now at lower pressure, you get less energy out of it when you decompress the tank. You've lost energy by cooling it, so you're effectively storing less energy now.

Re:Alternative power storage

[Moofie]

"When the tank has no pressure, there are x moles of gas in it. As you start adding more gas to the tank (you know, storing the compressed air) there's now y moles of gas in it, where y > x. In order to fit more moles of gas into the tank, the gas is cooled, which results in the gas exerting less pressure, and now you can fit more gas into the storage tank without violating the pressure spec on the tank."

100% agreed. Whether you can realize enough savings on the differential cost between AM and PM power usage, is a different issue. Please note that, at night, less energy is required to cool your house.

The OP also mentioned using the "waste" heat to heat water. OK, that's fine. But if that's what you're after, why not use a gas burner, or a (wait for it!) solar water heater?

You certainly can use heat differentials to produce energy. You cannot produce more energy than you used to create the heat differential in the first place. If you can find a "free" heat differential (geothermal, passive solar, etc.) then you can get a net energy gain within your system, because you've externalized the energy required to create the heat differential.

But there's no such thing as a free lunch.

"Taking cheap electrical energy to store energy and suck heat off in order to allow us to store more air, and use that excess heat where we want it"

Clearly, there's nothing in principle wrong with that. The engineering is a challenge. However, there is NOT NOT NOT free energy produced. The claim was an over-unity efficiency, and that's my issue: That is not possible. Period.

Re:Alternative power storage

[DeadCatX2]

By letting it cool down (T down), while holding the piston volume (V) and quantity of gas (n) fixed (you did claim no leakage as a stipulation), according to PV=nRT, the pressure (P) will indeed decrease.

Let's say the cooling caused the pressure to go from 6000 psi to 4000 psi. Now, you're well under the pressure spec for the cylinder, and you can now fit more gas (n goes up, P goes up) into it without violating the pressure limit.

Re:Alternative power storage

[DeadCatX2]

But you're storing more gas, which is the goal. And, when you pull the cool gas out of the tank, you can heat it back up to normal temperature (by, say, using it to cool the air in your house). Cooling the air in the house gives the air the energy that you stole from it when you cooled it down. Since you now have plenty of excess gas (since lowering the pressure allows you to store more moles of gas), assuming that you have sufficient heat to bring the air back to normal temperature, you should be able to recover the energy.

Re:Alternative power storage

[Anonymous Coward]

Do you have real numbers and actual equipment?

Do you have a reading comprehension problem? He does provide concrete numbers.

Specifically, he said it would cost exactly $40,000.00 to implement on any house, and achieve efficiency greater than unity. How much more precise do you expect him to get?

Re:Alternative power storage

[DeadCatX2]

Whether you can realize enough savings on the differential cost between AM and PM power usage, is a different issue

And OP replied to one of your comments with sufficient numbers for you to crunch to determine this issue.

The OP also mentioned using the "waste" heat to heat water. OK, that's fine. But if that's what you're after, why not use a gas burner, or a (wait for it!) solar water heater?

Because cooling the gas is necessary to store more of it. The necessity means that the heat will be generated whether or not you need it. If you have a sufficient source of heat already, why would you (wait for it!) want ANOTHER source of heat?

However, there is NOT NOT NOT free energy produced. The claim was an over-unity efficiency, and that's my issue: That is not possible. Period.

I agree with you, no free energy is produced. However, I think you misinterpreted the OP.

For one, did you completely miss the point where the efficiency in question is relative to the fucking dollar? He didn't explicitly state it but that was the gist I got when I read his post. Though, I read it without the intent on attacking him, and perhaps that allowed me to interpret his words in a manner different than yours.

This is how I interpret what he said.

We store energy when it's cheap, and use it when it's not. Part of this storage process generates heat. If we use the excess heat from this storage process, that is LESS energy that we need to use to create heat. Part of the unstoring process also absorbs heat. If we use this heat absorbing bit of the process to cool our house, that is LESS energy that we need to use to cool the house.

So, the reason dollar efficiency is higher is three-fold. The electricity itself is rendered less expensive via the storage mechanism, and they use two of the byproducts of the storage process for effects that we would normally use electricity for.

Re:Alternative power storage

[simm1701]

Thank you.

You finally convinced me to check my math several times - I'm afraid this is one of those cases where back of the paper napkin science still seems close to rational enough in the cold light of morning.

Actually the math is right, perfect, spot on, not a single mistake. As is all the specs. I'd gone over them myself a few times trying to convince myself of all this (as had obviously suceeded) - still not quite believing it I had checked up on all the individual things when sober and it seemed to all add up.

I found the problem though.

One calculation in the middle based on Charle's law when the situation it was describing had variable pressure (had to rewrite the calculations from scratch to find it - probably something I should have done on sunday but never mind)

Not sure which is stranger though the fact I didn't notice the problem or the fact my brain commonly goes on tangents like this (drunk or sober) though I normally just rule out random ideas much sooner.

I do think its important to be able to admit when you are wrong - and apologise to all concerned about the general content of this thread and blame it on only 16 hours sleep total in the last 96 hours (not to mention nearly being at the end of a 12 hour shift which I thank you all for the diversion you have given me this afternoon)

Re:Alternative power storage

[Moofie]

Aha! If you want to talk about dollar efficiency, you have to introduce a whole 'nother set of factors. It is theoretically possible to game the price differential and save money. Which is why I asked to see the OP's work. Which never happened. I assume that's because the OP is laughing so hard at my poor grasp of thermodynamics.

(Yes, that was with an eye roll.)

Re:Alternative power storage

[Moofie]

"For one, did you completely miss the point where the efficiency in question is relative to the fucking dollar?"

Yes. Yes, I did miss that. Which is why I asked for a more thorough explanation, which he graciously "simplified" by making a number of very, very wrong assumptions.

I agree with you 100% that there are ways to game the nighttime/daytime electricity cost differential to spend less money doing the things that we do. I agree that we could use math similar to the math used in thermodynamics to analyze that system. That is an absolutely do-able scenario.

Now, we have to discuss how you do it. The idea proposed is based on incorrect understandings of thermodynamics and is, therefore, suspect. It may be that by analyzing the system correctly, money could be saved. Had the OP given the details I requested instead of trying to simplify things for me, that discussion might have been productive.

He didn't, so it wasn't. GIGO.

Re:Alternative power storage

[Moofie]

"It was too much to hope that they would think for 5 minutes to understand what you are saying."

If somebody claims over-unity efficiency, they definitely have some 'splainin' to do.

Re:Alternative power storage

[simm1701]

Though if anyone can demonstrate a way this would work and still half an electric bill given 3:0 peak:offpeak pricing (the measure I figured would be the only viable option for it) I'll retract the above ;)

However given the tank specs I was looking at (tanks hold 540CF of air at 6000psi) I can't see you getting the temperature differential during compression I was thinking of (my original math came up with a delta T of over 100K but I explained why that was incorrect) I can't see it happening unless you expend more energy to compress the gas to raise the heat and pressure before you cool it and I suspect (though I could be wrong) that its cheaper to just heat the water...

You would still get some cooling effect and the 64% efficency on storage is correct (and for me would still be a small saving) but to be honest I think I'll just install a heat pump.

Re:Alternative power storage

[Moofie]

You're welcome? I think?

I can't analyze your system without evaluating your assumptions. The best way to do that would be for you to share your math with me. If you don't want to do that, that's cool...it's a lot of work. No big deal.

Or maybe you're still laughing at me. If so? Enjoy yourself. Good luck with your perpetual motion machine. If you get it to work, I'll gladly buy one from you.

Re:Alternative power storage

[Moofie]

If you really have a 3:0 price differential (meaning that you get free electricity at night), I think your system will absolutely work. I can think of a lot of other systems that will work a lot better.

Since I really think you don't, I'm still skeptical.

"but to be honest I think I'll just install a heat pump."

Hmm...you mean a simpler mechanism might be more efficient than a complex one? What a stunning revelation.

Here's another simple mechanism for you. Use your cheap nighttime power to run a pump that moves water into a tank on your roof. Have the tank painted black.

Hot water. Power reservoir. No "free" air conditioning, but I didn't really grok how you were going to work that part anyhow. (as an aside, I'd love to see the electrical schematic for your thermostat system.)

Re:Alternative power storage

[simm1701]

The assumption was that you could store this compressed air, and that in compressing it it would get hot and that you would have to cool it - that cooling could be used to heat water and you would still have the compressed air.

The original thoughts came in between discussing the new compressed air car motor and ground source heat pumps

Getting over 100% effective efficeincy (though not actual efficiency) is obviously easy with a heat pump - 400% is feasable I beleive - though its obviously a different mechanism of effectively moving heat from one place to another - not trying to pull it out of the same process twice in different ways.

Since you are familiar with this please do just double check my assumption in discarding all of this:

If you compress 540 cubic feet of air, to 6000 psi and store it in a 1.323 cubic foot cylinder at 6000psi then the heat gain is going to be negligable? (there will be some at the pump I suspect, but the system as a whole will just balance out)

Re:Alternative power storage

[simm1701]

3:1

The free air con was that as the air comes out of the cylinders its going to decomress and cool down and if you pump that through your house as it does.

As I said - misuse of Charle's law gives interesting results.

Re:Alternative power storage

[Crispy Critters]

Of course; that is why it is so important to understand what is meant by "efficiency" in the context in which it is used. If someone says they are converting one form of mechanical energy to another form of mechanical energy with greater than 100% efficiency, then he is lying. On the other hand, the efficiency of a heat pump is calculated as heat output divided by energy input and is always greater than 100% (for the abstract heat engine cycle, not a physical unit - since these often double as ACs, the waste heat is outside instead of inside and practical efficiency can be low).

The numbers might not work out (does the hot air get hot enough to aid the hot water heater? can the various streams of cold and hot air be moved around effectively?) but if we define efficiency as the electrical output plus the electricity to provide the same amount of hot water and cold air (resistive heating and conventional AC respectively) divided by the electrical input, then we might get a number greater than 1.

If you then use the hot water and cold air to generate electricity, you will of course end up with less electrical power output than you started with. You can never get above 100% efficiency by that definition.

Re:Alternative power storage

[Moofie]

"not trying to pull it out of the same process twice in different ways."

Here's the thing. Your compressor is the only source of that heat. If you want to use energy to heat water, it's more efficient to just do that, rather than using your system. If you want to use energy to cool air, there are reasonably efficient ways to do that.

Each leg of this process (heating water, cooling air in your house, pressurizing air into your tank) have thermodynamic losses associated with them. Evaluating and minimizing these losses are the key to making a system like this work economically.

I'd have to look at my thermo book to perform the analysis. Believe it or not, I'd be glad to do so...but my textbooks are in storage. Maybe when I get home I'll do some hunting and see if I can come up with some back-of-the-envelope calculations.

Is it possible? Anything is possible. Is it likely to work? It sounds pretty Rube Goldberg-y to me.

As a thought experiment, fine and dandy. As a teaching tool, it's probably great. It'd be a great thermo test question. As a machine to save your money? Hmm...might want to just buy some bonds instead.

Re:Alternative power storage

[DeadCatX2]

Now, we have to discuss how you do it. The idea proposed is based on incorrect understandings of thermodynamics and is, therefore, suspect.

But, didn't you originally state that the incorrect understanding was the >100% efficiency claim? So, which part of his idea disagrees with thermodynamics?

Keep in mind, I'm no M.E. and I only know a bit about the subjects at hand because of some college physics. I only chimed in on this discussion in the first place because I saw that OP was discussing efficiency relative to the dollar, and a lot of people started flipping out over his efficiency claim.

The only thing that seems shakey to me is decompressing the air to cool your house. Is it really possible to give the air enough energy to drive the turbine by letting it cool your house? I would assume it would be more beneficial to try to superheat the air to increase its pressure, assisting it in the process of driving the turbine.

Re:Alternative power storage

[tepples]

in order to not violate it, you decrease temperature, T, you decrease pressure, P, because the ideal gas law states that pressure and temperature are directly proportional in a fixed volume.

PV=nRT What happens when you change n, holding V and T constant?

Re:Alternative power storage

[Moofie]

The part where the OP thought that if you have hot gas in a fixed volume, and cooled the gas, the pressure would stay constant. Any system built on that assumption needs further analysis.

As soon as I got to the OP's actual notion (see another branch of this conversation), I found the assumptions that were actually being made, and corrected some misconceptions. For fun, I'm looking at actually designing a cycle based on these principles, just to see if I can do it.

It looks like we're not cooling the house by electricity produced by a turbine, but by expansion of the cool, compressed gas. Is that theoretically possible? Sure. Is it likely to be controllable by any sort of thermostat? That's going to be harder. And, oh yeah, when you're not using that jet of cool air, you also don't get any electricity.

Re:Alternative power storage

[Moofie]

Then the pressure changes, linearly with n.

Re:Alternative power storage

[njh]

I believe the 540 cft refers to the amount of STP gas that is stored inside. It's all squashed up in there (sort of like a change in space time or something).

Re:Alternative power storage

[njh]

*eyebrow* I'd like to see your work there, cowboy. Most of the time, thermodynamic processes don't give above-unity efficiency. And by "most", I mean "absolutely all".

It's called a heat pump, and he means COP. The idea is just a standard gas compression refrigerator with storage. You can do much the same with a phase change system (i.e. normal refrigeration). More interesting is open cycle absorbtion cycle systems based on say LiCl and water.

Or, you could do as I do and just use a big box of water to even the temps out between day and night.

Re:Alternative power storage

[njh]

It looks like we're not cooling the house by electricity produced by a turbine, but by expansion of the cool, compressed gas. Is that theoretically possible? Sure. Is it likely to be controllable by any sort of thermostat? That's going to be harder. And, oh yeah, when you're not using that jet of cool air, you also don't get any electricity.

Not to mention danged noisy. It does work though. There are proposals to use high pressure air to power military computing bunkers for both energy and cooling needs.

Re:Alternative power storage

[woztheproblem]

You're being ridiculous. Storing more gas doesn't help if it's at lower pressure. The power is generated by the gas forcing it's way out of the tank. So, the energy released is going to be the product of the pressure differential and the amount of gas. If you lower the pressure, you're losing energy, plain and simple. And if you had extra heat to spare to start with, you should have used it to heat the water that you were talking about earlier. There's no need to send that whole energy transfer through the gas. It's a separate process if you just want to move heat from your air to your water.

Re:Alternative power storage

[DeadCatX2]

Perhaps, but, consider that you want heat and cool at different times. In the right place, during the day you would have spare heat (sunlight, environment) to heat the gas again, because during the day is when you want to use the gas to push your turbine.

And, during the evening, when it's not so hot out, you'll be compressing the air, and that's when you generate heat to do everything else.

Just like we timeshift the usage of cheap night time energy into storage for use in the daytime, we also timeshift the usage of heat.

Re:Alternative power storage

[Anonymous Coward]

On this website, we obey the laws of thermodynamics!

Yes, to a certain extent

[Flying pig]

Operating costs of power plants vary, with large coal fuelled plants usually the cheapest and small gas powered plants the most expensive. So you run the baseload on coal and nuclear and switch in the more expensive plants as you need them. In the US in summer highest demand is during the day,so everything gets switched in and the rate is higher. At night you can run on baseload and the cost is lower. There is a lot more to it than that including the effects of energy dealing, but basically that's why solar power makes sense in Ca and Az - you need your power when the sun is shining. In N Europe where our demand is more balanced and the sun is at a lower angle, wind and wave make more sense because they run 24 hours per day (somewhere)

Re:Yes, to a certain extent

[LWATCDR]

Actually I believe that Hydro is the cheapest followed by Nuclear or Coal. Other than that you are right on the money.

Re:Yes, to a certain extent

[NeutronCowboy]

The other part I'd like to point out is that very plants actually get switched off. The only time a power plant is off is when it needs maintenance - and then the plant is offline for a few months. I think the prices reflect simple supply and demand - demand goes up and supply stays constant. Therefore, prices go up.

EXPENSIVE !!

[polar red]

> 29.7 to 35.9 WTF ???
I pay 0.1008 € per Kwh (and that's green electricity ...) (that translates to about 0.13$ per Kwh. And about half that at night.

Re:EXPENSIVE !!

[ChefInnocent]

WTF indeed! California Edison and PG&E have always bilked their customers for as much as they can. They know they have a very profitable localized monopoly. I live in Idaho (just a couple of states away). We pay $0.055/kWh. Whether our power is green or not is up for debate; the bulk of it is hydropower. Never the less, even ours is significantly cheaper.

Re:EXPENSIVE !!

[popeye44]

Yep, Last July I went over the highest allowed KWH trying to keep my house at 85F. I paid .33kwh for PG&E. My average bill is currently 403.00 a month. Because I have them average it out over the year. My July bill was over 950.00. Now you might think I have a huge house.. pool etc. This is a 4 bdrm 2 bath house that was built 70 years ago 1605sq ft. A good bit of the bill is because of the AC unit. I'm hoping like hell the new one makes the bills lower.. I'm about to die from em.

Re:EXPENSIVE !!

[polar red]

Insulate your house like hell, friend. You're gonna have a huge ROI.

Re:EXPENSIVE !!

[Anonymous Coward]

Wow, where the hell are you? My house is a 4/2/2 ~2250sq ft, so not too dissimilar. Yet our power bill is nothing like yours. The peak in FL summer is under $200, down to around $70 in the spring and fall, and that figure includes fees and filters running around $15/month. Summer includes a fair amount of pool pump usage due to it being our rainy season and the fscker turning green with the rains. I ramp the hours down on that when we're dry, like now.

Have you checked your windows and doors for air gaps? Caulking them will be cheap and easy. Ensure you do inside and out, ans use waterproof caulk.

Do you have access to the attic? Aluminum radiant barrier is reasonably simple (easier with 2 people) to install with a powered staple gun, and will run you about $100 for 4 x 100' roll. I knocked over 20 degrees off of our attic temperature installing that stuff.

Re:EXPENSIVE !!

[doktor-hladnjak]

Expensive energy prices are probably still around from the power crisis a few years ago. The artificially manufactured rolling blackouts made international news at the time. Here in Seattle, we only pay about 4.5 cents per kwh, which typically gives me a power bill of $15 every two months. Then again, something like 90% of the city's power comes from hydroelectric.

Re:EXPENSIVE !!

[Damvan]

As a Southern California Edison customer, without TOU, I pay $0.19 kwh for the lowest tier. Depending on the highest tier you hit, it can be as high as $0.50 kwh. My solar system produces about 75% of my electricity needs. The big advantage is that for any electricity I have to buy from SCE, I only pay the lowest tier. So while I still have to purchase 25% of my electricity needs from SCE, my bill is only 10% of what it was prior to the solar system.

Re:EXPENSIVE !!

[dsgrntlxmply]

Planck says that your electricity is cheaper because it is green, and therefore inferior in energy. If you put enough of our better, higher-energy American electricity into one place, it tends to be blue or purple.

"It's the Economy, Stupid"

[slashdot.cc]

More evidence that Economics class(es) should be mandatory in the public school curriculum.

Panels not ready for prime time

[Anonymous Coward]

When one buys solar power he is paying for all the electricity costs for 10, 20+ years up front. So when the house does not have enough square footage to provide power through the peak-hours then supplemental power needs to be purchased and the owner of the house is now paying twice for power. Solar power is not rocket science, but people need to be better informed about how the solar power equation works. Finally, until solar power efficiency improves there will be plenty of people who won't have enough roof space to get back their ROI on the investment and thus solar power won't be a popular option until 2 things happen; the panels cost less and are more efficient in coverting light into electricity.

As far as batteries are concerned this is called "power caching" and can be used without solar. I can store all my power for the next day after charging the batteries overnight when the rates are super low - theoretically speaking that is. The solution, before solar, is to sell people "power caching" systems on the grid and then pull that power down during peak times and during brown/black outs.

I love the idea of solar, but until the cost comes down and efficiency goes up there is very little point to struggle with small home systems.

Re:Panels not ready for prime time

[AtariDatacenter]

I like this idea. Very interesting!
(I guess the question then becomes... lifespan of the batteries? Cost of caching equipment?)

Re:Panels not ready for prime time

[Paulrothrock]

I've heard stories from solar power installers about people wanting to install systems on top of a hill surrounded by trees that would only get about 4 hours of light a day, meaning that they'd need about 50% more panels than normal to cover the cost. Then the installers go into the house and see conventional light bulbs and old, inefficient appliances and just shake their head.

It would be better for people to be spending money increasing efficiency and tightening up their houses than to buy whole new solar panels.

And if they're going to be putting up solar panels, why not do it in an intelligent way? For about $600, you can take one or two rooms off of the grid entirely with a system that will scale easily by adding another charge controller or inverter. I'm hoping to take my fridge off the grid in a little bit for about that price, with the added benefit of keeping my stuff cold when the power goes out.

Re:Panels not ready for prime time

[Squirmy McPhee]

Finally, until solar power efficiency improves there will be plenty of people who won't have enough roof space to get back their ROI on the investment and thus solar power won't be a popular option until 2 things happen; the panels cost less and are more efficient in coverting light into electricity.

Agree on cost -- right now it's about 2.5x more expensive than the average grid rate in California -- but you're dead wrong about roof space. Using the least efficient cells available a 10 kW PV system will require about 1600 square feet of roof space, which a home large enough to need a 10 kW system would almost certainly have available. Using cells of average efficiency reduces that to less than 1000 square feet, and using the highest efficiency cells brings it down to about 600 square feet. And not only do the cells cost about the same per watt regardless of efficiency, giving you plenty of flexibility on how much roof space you use, you can cut those areas in half for a typical home.

Re:Panels not ready for prime time

[aaarrrgggh]

Not to be a smart ass, but have you heard of 2-story homes?

With odd roof shapes, even a ranch home can have a limited amount of south-facing roof.

Re:Panels not ready for prime time

[Squirmy McPhee]

Not to be a smart ass, but have you heard of 2-story homes?
With odd roof shapes, even a ranch home can have a limited amount of south-facing roof.

True, and not all homes have south-facing roofs. However, I've been involved in the solar industry for over a decade and have yet to meet the owner of a single-family home that seriously pursued solar power and gave up because the panels wouldn't fit on the roof. It wouldn't surprise me in the least if there's one out there somewhere, but it certainly isn't an issue that's keeping anybody up at night. In fact, there's a sizeable portion of the industry that believes solar cell efficiency is irrelevant and all that matters is cost (and many of those folks are quite experienced in installing solar systems in single-family homes).

Of course, a key element of properly sizing a PV system that a lot of people miss is that it's cheaper to upgrade lighting and appliances to high-efficiency models than it is to buy extra solar panels to power the devices most folks already have in their homes. As a result, solar-powered homes typically use significantly less energy than an equivalently sized, conventially powered home. That, of course, further reduces the need for roof space. Look at a few photos of solar-powered homes -- even those that have multiple stories -- and you'll see that it is rare that the entire roof is covered with solar panels.

Re:The math will never come out with current panel

[hswerdfe]

solar is also good for non electrical use.

Pasive Solar energy tends provides much better ROI then active solar.

WTF?

[Anonymous Coward]

Dude, can you really stop it with this crap?

Well, let's do it differently:

END-USER LICENSE AGREEMENT FOR MICROSOFT SOFTWARE

This End End User License Agreement (EULA) is for informational purposes only. There is no software accompanying the EULA.
MICROSOFT WINDOWS XP PROFESSIONAL EDITION SERVICE PACK 2

IMPORTANT--READ CAREFULLY: This End-User License Agreement ("EULA") is a legal agreement between you (either an individual or a single entity) and Microsoft Corporation or one of its affiliates ("Microsoft") for the Microsoft software that accompanies this EULA, which includes computer software and may include associated media, printed materials, "online" or electronic documentation, and Internet-based services ("Software"). An amendment or addendum to this EULA may accompany the Software. YOU AGREE TO BE BOUND BY THE TERMS OF THIS EULA BY INSTALLING, COPYING, OR OTHERWISE USING THE SOFTWARE. IF YOU DO NOT AGREE, DO NOT INSTALL, COPY, OR USE THE SOFTWARE; YOU MAY RETURN IT TO YOUR PLACE OF PURCHASE FOR A FULL REFUND, IF APPLICABLE.

1. GRANT OF LICENSE. Microsoft grants you the following rights provided that you comply with all terms and conditions of this EULA:

1.1 Installation and use. You may install, use, access, display and run one copy of the Software on a single computer, such as a workstation, terminal or other device ("Workstation Computer"). The Software may not be used by more than two (2) processors at any one time on any single Workstation Computer.

1.2 Mandatory Activation.The license rights granted under this EULA are limited to the first thirty (30) days after you first install the Software unless you supply information required to activate your licensed copy in the manner described during the setup sequence of the Software. You can activate the Software through the use of the Internet or telephone; toll charges may apply. You may also need to reactivate the Software if you modify your computer hardware or alter the Software. There are technological measures in this Software that are designed to prevent unlicensed use of the Software. Microsoft will use those measures to confirm you have a legally licensed copy of the Software. If you are not using a licensed copy of the Software, you are not allowed to install the Software or future Software updates. Microsoft will not collect any personally identifiable information from your Workstation Computer during this process.

1.3 Device Connections. You may permit a maximum of ten (10) computers or other electronic devices (each a "Device") to connect to the Workstation Computer to utilize one or more of the following services of the Software: File Services, Print Services, Internet Information Services, Internet Connection Sharing and telephony services. The ten connection maximum includes any indirect connections made through "multiplexing" or other software or hardware which pools or aggregates connections. This ten connection maximum does not apply to other uses of the Software, such as synchronizing data between a Device and the Workstation Computer, provided only one user uses, accesses, displays or runs the Software at any one time. This Section 1.3 does not grant you rights to access a Workstation Computer Session from any Device. A "Session" means any use of the Software that enables functionality similar to that available to an end user who is interacting with the Workstation Computer through any combination of input, output and display peripherals.

1.4 Remote Desktop/Remote Assistance/NetMeeting. The Software contains Remote Desktop, Remote Assistance, and NetMeeting technologies that enable the Software or applications installed on the Workstation Computer (sometimes referred to as a host device) to be accessed remotely from other Devices. You may use the Software's Remote Desktop feature (or other software which provides similar functionality for a similar purpose) to access a Workstation Computer Session from any Device provided you acquire a separate Software license for that Device.

It's called supply and demand

[sxltrex]

During the day, especially during the summer months, demand goes way, way up. Supply is (for the most part) constant. Therefore, the market will bear higher costs during the day. It has nothing to do with the cost of producing the power.

Keep in mind, though, that most residential customers don't currently see this change--their rates are held constant, and they're billed based solely on their total monthly KWh usage. Only TOU customers (mostly C & I, or big users) fall into the changing rate category. Part of this is due to the fact that TOU meters are expensive, and replacing (using SCE as an example) 4,000,000 residential spinning disk meters with TOU meters at $200-1000 per unit is cost prohibitive. Of course, this is all going to change with the advent of AMI (Automated Metering Initiative).

Re:It's called supply and demand

[Rob the Bold]

It has nothing to do with the cost of producing the power.

Not quite true. The costs of producing any good factors into the supply curve. To say that the production costs don't enter into it, would be the law of "demand and demand", I guess. Electricity is highly perishable, so the supply and demand equilibrium is different at different times of day.

I'm an EE, but not a power engineer. My Dad was, and we talked about his work a lot.

The capital costs of generating power vary with peak demand. The higher the peak demand, the more generating and transmission capacity you need. It doesn't really matter if the peak is at Noon or 4pm or midnight, the scale of the "plant" required is determined by this peak demand value.

So if you are in the business of selling electricity, you'd like to keep capital costs down, since these affect your fixed costs, and you charge more for power during peak hours (shifting the supply curve at that time) to reduce demand.

Another method is to charge a "demand charge" based on a customer's largest peak demand. This encourages commercial customers to keep their demand flatter, or even install load shedding devices to create their own local blackouts at their facilities to prevent their peak demand from exceeding a threshold that they are unwilling to pay for.

Electric customers can save money on electricity by buying it "off-peak". For a factory, this might mean running evening and night shifts. For a residential customer, this might mean installing an automatic thermostat, for example. As you said, though, most residential customers in the US do not pay for electricity at different "peak" and "off peak" rates, and most are not subject to a demand charge.

Live Solar PV stats at Toronto Exibition Place

[rohar]

The Toronto Exibition Place 100kW Solar PV demonstration project cost $1.1 million and they have a mixture of panel vendors.

They estimated 22 years to reclaim the investment at $0.42/kWh under Ontario's Standard Offer Program. Which is allowing $0.42/kWh for PV and $0.11 for all other renewable systems.

You can watch the live output stats (requires flash) of the Exibition Palace 100kWh installation in Toronto and see historical data.

The system has been online since last August and they should have a much better month this June, but the 100kW Solar PV installation poorest functional month was 1.8MWh (January) and best was 9MWh so far. At the $0.42/kWh this translates to $756-$3780 per month or 24-121 years to reclaim the investment. At $0.11/kWh this is $198-$990/month or 92-462 years to break even on the investment.

I would think the real annual output will land in the center and at the $0.42/kWh rate, they will reclaim the $1.1 million in around 40 years if the panels output doesn't degrade severely through that period.

In higher annual insolation areas like California and Hawaii with peak electrical usage due to AC, solar PV is getting better for low-maintenance installations like a Walmart or Google roof, when the PR factor is taken into account, but in Canada, it's a long way off from feasible due to the low winter insolation and "Twin Peaks" electrical load with the highest peak in February when solar PV has no real output.

SHPEGS is our attempt to design a more suitable renewable power system for Canada, Northern US and Europe.

Re:Live Solar PV stats at Toronto Exibition Place

[rohar]

I have some real issues spelling "Exhibition" :)

Re:Live Solar PV stats at Toronto Exibition Place

[ChrisMaple]

Your figures are bogus because they ignore the time value of money (a.k.a. interest). At 4% interest and the most optimistic value of generated electricity (at the absurd $0.42 per kWhr) the payoff time is 600 years. Anything worse and it will never pay for itself.

Re:Live Solar PV stats at Toronto Exibition Place

[rohar]

It's a demonstration and there were several grants and interest free loans, I also didn't account for panel degradation, interest, wind damage etc.

Anyway, the 1.1 million for 100kW is trivial. Even with these kind of numbers on a demonstration project, OptiSolar signed a deal for a 40MW Solar PV project in Sarnia on this same $0.42 contract. Optisolar doesn't actually have a commercial thin film Solar PV product. The /. coverage Canada to Build 40MW Solar Power Plant

Anyone else notice where part of the fault is?

[MikeRT]

The unintended glitch was created in December, when the PUC moved to implement the law by requiring that solar users switch to the higher "time of use" rates for their supplemental electricity.

Why is the government forcing private citizens to enter into a relationship that is advantageous to the electrical companies and utilities? It's bad enough that they force people to do that with insurance companies, now it's with electricity too. Why not just follow up with food, water and medicine while we're at it?

Cut out the middleman... it's cheaper

[Nymz]

People should make their decisions based upon their own situation and ability and commitment. Inserting a middleman or politician, in order to decide which industry will be a winner and which will be a loser, means citizens will always be the losers.

Rebates are not free, solar equipment has a cost to manufacture. Playing a shell game with rebates, and then flucuating power company rates, only do one thing, and that's make the change to solar more complicated and less predictable to calculate the cost over time.

I suggest following the advice written in the preable to the US Consitution. For the government to promote the general welfare, not provide it. To fund studies and publish information on how their state citizens can best make use of alternate energy. Not to pick companies that contributed to their reelection campaign, and then pass out government rebates for that companies product or service.

Re:The math will never come out with current panel

[Lumpy]

If you are a moron and buy all your Solar panels new? yes you are 100% correct.

If you are wise and buy used solar panels for $0.05 on the dollar, clean them up yourself and fix the ones that havwe broken connections. You get power at less than current rates. At least that is what I got for 5 years before I moved.

new stuff is insane priced, and problem is these "green feeling" rich people want the shiny blue looking panels instead of the yellow and faded brown ones I use. and honestly having solar at your home is more advanced than the typical homeowner can handle. you need to have a clue about electrical and electronics or a really DEEP checkbook to pay the specalized electrician as most regular sparky's freak out when they see solar or wind power.

Having solar on your home is only for the technically advanced as you really need to maintain it yourself and understand it. Going out 3 times a year on your roof to clean the panels is not something Rich joe BMW driving homeowner is going to do. And you do not want someone that does not know what they are doing up there to cause a few thousand in damage and take you offline.

my numbers

[bcrowell]

I'm in exactly the situation described in the article. I've gotten my first quote on a solar system, and will get my second quote next week. I'm trying to figure out if the whole thing makes sense financially, and the TOU requirement certainly doesn't help. Data on the quote I have:

• 5.2 kW nominal power, 4.4 kW output from the inverter
• estimated yearly output of 7600 kW.hr
• $40,900, lowered to $28,100 by rebates
• 468 square feet

Last year we used about 12,000 kW.hr, which cost us $2,400. We've instituted a bunch of conservation measures, which should make that figure a lot lower in the future. The critical thing is the summer months, when we'd sometimes been using 1500 kW.hr per month. This is partly the pool pump (which you have to run longer when the water temp is higher), but mainly AC. Actually although we're in Southern California, our house stays pretty cool naturally, and often we go a whole summer without turning on the AC for more than a few days, but there's always the temptation just to turn on the AC because it feels more comfortable. We just signed up for a voluntary program where Edison installs a remote control on your AC and turns it off at peak times, in return for which they give you some money. We've also started using the pool pump for fewer hours per day, which seems to be working OK as long as I'm very careful about all other aspects of pool maintenance.

If we hadn't instituted any conservation measures, and if the legislature doesn't backstep on the TOU thing (which seems to have been simply a mistake), then I'm estimating we'd only save about $1,250 per year with the solar system, which isn't much of a return on a $28k investment. Judged purely as an investment, we'd have been better off just putting the money in the bond market or something.

On the other hand, if we do the conservation measures, then the TOU might not be such a big deal, because we wouldn't be buying much energy at the summer, peak rate of $.36/kW.hr. My estimate is that if we hardly ever turn on the AC (which we've done in some summers), then the TOU thing becomes financially irrelevant to us, and the system saves us about $1,500/year, which is somewhat better. It becomes an investment sort of similar to a standard real estate investment, where you pay a bunch of money up front, and then get a steady for a long time. One big issue is that you want to make sure your system lasts long enough so that it pays for itself, and that means you want to have confidence in your warranty. The good news is that the companies I'm getting quotes from have been in business for 40 years. The bad news is that the LA Times is quoting them as saying that unless the legislature reverses the TOU requirement, they'll all go out of business within 100 days.

The real issue is global warming. If it's reasonably neutral in investment terms, then I'm inclined to do it, but it's worrisome to have this cloud of uncertainty.

Re:my numbers

[radtea]

On the other hand, if we do the conservation measures, then the TOU might not be such a big deal, because we wouldn't be buying much energy at the summer, peak rate of $.36/kW.hr.

The cheapest, cleanest energy you can buy is the energy you don't use. Until you've squeezed your energy use down to the smallest reasonable level (where you'll have to provide your own definition of "reasonable"!) it is unlikely to make financial sense to make a major investment in solar or any other type of alternative power.

That said, you have clearly identified your pool pump as a large load, and there are companies that sell solar energy units that are aimed directly at that particular point load, for example: http://www.etaengineering.com/pool_pump/intro.shtm l That was just the first hit on googling "solar power pool pump"--there were lots of others. It may make sense to make a much smaller investment to reduce this load. One interesting aspect here is that the system may include a DC motor, so you avoid the inverter loss, which is fairly significant.

As we think about alternative energy we need to move away from the "universal plug" idea of traditional on-demand energy sources, and focus on disruptive uses that do not serve every imaginable need, but which are well-matched to particular needs.

Re:my numbers

[Llywelyn]

Assuming you save $1500 a year after the first year with a $28100 initial investment (and assuming my back-of-the-envelope math is right), it would take you 57 years to beat a 5% annualized rate of return (and assuming no expenses). You could do it in 19 years, however, if you could find a way to get $2400 in savings either directly or by selling energy back.

Re:my numbers

[Rich0]

If your electric bill is $2400/yr, and even with subsidies your panels will cost $28k, then you're looking at at an 11-year-plus break even at zero interest and going off the grid entirely. If you finance those panels at 4% over 10 years they'll cost you $34k in total - so you're still 4 years behind breaking even after a decade.

Now, if you can get by with fewer/cheaper panels or if the cost of grid power goes way up then the economics might change. However, the figures don't even look close to break-even as they currently stand...

Re:my numbers

[bcrowell]

If you finance those panels at 4% over 10 years
I'd have to be nuts to borrow money to build a PV system. The savings would barely be enough to service the debt.

Now, if you can get by with fewer/cheaper panels
No, the economics get worse if you downsize. The new requirement of TOU metering means that in summer peak hours, you pay $.36/kW.hr if you install photovoltaics, whereas if you don't install PV, you can stay with domestic D rates, which are about $.20/KW.hr. Unless the legislature admits it made a mistake and gets rid of the TOU requirement, the only way to make one of these systems economical is to have a big enough system that it supplies almost all of your electricity needs during summer peak hours.

Re:my numbers

[bcrowell]

Assuming you save $1500 a year after the first year with a $28100 initial investment (and assuming my back-of-the-envelope math is right), it would take you 57 years to beat a 5% annualized rate of return (and assuming no expenses).
One possible problem with your assumptions is that electric rates probably will not stay constant; they'll probably go up. California currently is not allowing any more nuclear power plants to be built. There is also no real room for any major increase in fossil fuel plants (NIMBY, global warming concerns, ...), and the price of fossil fuels can only go up in the long term. Meanwhile the population is going up, and the per capita use of energy is going up. So really, investing in a PV system at this point is partially just a gamble on how much electric rates will go up in the future.

Re:my numbers

[Llywelyn]

That's a good point, I hadn't considered that. It is less of a problem in my neck of the woods at this point in time, so it completely slipped my mind.

If the price goes up 10%/year, compounding annually and starting at $1500/year, then you will recoup the investment vs. a 5% interest rate in 15 years.

Re:my numbers

[Big_Breaker]

That assumes the price of electricity doesn't go up. It you charge an interest rate you ought to credit a cost inflation rate. I think the cost will rise faster than a typical mortgage rate. Also the variability is asymmetrical.

Electricity costs can't drop below zero, any drop is unlikely. They can however double and you'll be waiting in a long line with everyone else to buy and install those panels.

Re:my numbers

[Big_Breaker]

Some purification technologies also need less circulation. That would be worth looking into. You can also look at using a timer to run the pump at night for a TOU pricing improvement.

Re:my numbers

[Rich0]

I'd have to be nuts to borrow money to build a PV system. The savings would barely be enough to service the debt.

If you are borrowing any money at all, then that money you're using for the PV system could be used to retire that debt, for the same savings.

And if you aren't borrowing any money at all, you could put that money in safe investments and make that kind of money.

So the interest comparison is pretty relevant. If the PVs break even they're still a net loss from a time-value-of-money standpoint...

Re:my numbers

[Rich0]

Electricity costs can't drop below zero, any drop is unlikely. They can however double and you'll be waiting in a long line with everyone else to buy and install those panels.

Possibly true, but when those prices double I'd be happy to wait in that line to avoid a potentially negative investment now.

As an aside I can't believe the insane rates being tossed around in this discussion. My costs are under a dime per kWh. If I were paying upwards of 20 cents I'd certainly be rethinking the economics of PVs...

Re:my numbers

[j-beda]

Just to keep the math easy: your investment is $28K and your return is almost $1.4K, so you are looking at a return of about 5%. You have already seen what the payback time for this is, but one factor that hasn't been mentioned is that investments that reduce expenses like this are really equivalent to tax-free returns. Investing the money in stocks might give a greater rate of return (long term numbers are like 10%) but you have to pay taxes on that income, while you do not have to pay taxes on the money you save by installing solar. With a reasonable income, the tax you pay can quickly cut what looks like a large return to something much closer to the 5% you are calculating above.

With all that said, I recall seeing that the best rate of return (much higher than stocks, etc.) can be had by investing in a solar water system for your hot water needs. Even in Canada, it is possible to get more than 50% of your hot water needs via solar, and I am sure that most readers here are in places with better numbers than that. These folks claim a return rate of around 15% - and again this is "tax free".

Fuzzy Math

[Anonymous Coward]

"Fuzzy Math" is a Bushism. By using it, you're making yourself look like an idiot.

Thought you should be aware. :)

Re:Fuzzy Math

[mgabrys_sf]

re:""Fuzzy Math" is a Bushism."

Bullshit. As a metaphor it's been around longer than Bush - so fuck you.

Re:Fuzzy Math

[Locutus]

LOL, but the "idiot" tie-in was great. IMO

LoB

Re:The math will never come out with current panel

[bahwi]

Why are hybrids a gimmick? With the tax credit most hybrids pay for themselves within a year, although some people who drive less it takes up to one and a half years. Only new, not used. And fossil fuel infrastructure has a huge enviromental cost to produce and solar panels are easily winning that war. Nothings perfect, and as we go forward you won't be energy neutral because energy is what we need, but setting in stone the things now is good.

And not 10 times, fossil fuels only need to increase to twice the cost right now. You're solar math is old, we have new panels, they continue to get more efficient, and the early adopters create a market for it which urges people to create even better ones. Energy neutral is really a myth, nothing will ever be. Solars tend to make up for their cost within 5 years(depending on location).

Re:The math will never come out with current panel

[hey!]

Everything you talk about depends on scale.

The cost of solar panels includes amortizing the fixed costs of production over a small number of units.

The environmental impact per unit of photovoltaics is a function of low adoption rates. Imagine the environmental cost of the first petroleum refinery if it was built with subsidies to serve a very small petroleum market. Imagine we live in a world without any photovolatics. Would you expect the first plant to yield net environmental benefits? The first ten?

The current efficiency of photovoltaics reflects a low level of technological and manufacturing investment, which in turn reflects a low volume market.

The point of developing renewable energy resources is to hasten the day when they can be supported sustainably and responsibly using free market economics. This is motivated by a projection of the current petroleum based economy reaching the end of viability in the next few decades. Capital does not care, because capital is mobile. It will take high returns today, take some loss when the petroleum economy starts to falter, then move to newly attractive technologies when that day comes. With globalization, it can afford to forsake America, seeking higher returns elsewhere.

Meanwhile the people who have to live through the change are going to have a rough ride economically and environmentally.

In a sense, you can think of the environmental impact of photovoltaic experiments as a kind of invested environmental capital.

solar and hybrid myths

[SuperBanana]

The math with current photovoltaics will not come out in favour until the fossil fuel rises by a factor of at least 10 times. Does not matter what, how, who, where. They are simply too expensive to provide a reasonable ROI. They also have a very high environmental cost to produce so people who buy them are not doing a lot of good to the environment.

This is a myth often repeated. I'm going to simply point to a google search that will net many informative results. You'll find numerous calculations which all come to similar conclusions: solar panels have an "energy payback" of a few months to a few years, and their warranties extend well beyond the point where they become a source of income for the owner. This does NOT apply if you cannot place the panels where they will collect sunlight, or a geographic region which does not get enough solar power; there are plenty of online and physical tools to help with the evaluation of both. Solar power is not for everyone, just like hybrids are not for everyone.

There's one big caveat: wattage ratings for most panels are slightly inflated, because they're based off standardized tests using light sources which generate more light energy than you can find here on planet earth. Some manufacturers and retailers are upfront about this; others are not. Size the system off calculations based on your location, not spec sheets.

Photovoltaics are a gimmick, similar to the hybrid cars which allow metrosexuals and hollywood stars to show off some fake green credentials.

As a horsepower lovin' pistonhead, I eye hybrid owners' "my car runs on lolipops and giggles" attitude with some amusement (buying a car that burns gas does not "help reduce our foreign dependency on oil", if you understand that we have to buy oil from many sources for the nation's economic stability, no matter how much of it we use...and that consumer gasoline usage pales in comparison to commercial sector use, namely, petrochemical and truck/train/plane fuel), but hybrids DO most certainly make sense for heavy urban driving, which is exactly what they were designed for in the countries where they hit the public retail market big time: Japan. When Toyota came out with a full-size hybrid (Camry), they've been popping up all over Boston as taxicabs. The two keys are a)heavy usage and b)urban or other stop-and-go driving. Without the heavy usage, the gas savings don't compensate for the additional energy+materials (and hence additional price), and without the stop-and-go driving, hybrids are no more efficient than cars with similar drag-reducing design but regular powertrains.

Hybrids do not make sense for highway cruising commutes, which many people bought them for in the initial craze, mostly because they didn't do their homework. If your drive does not involve a fair amount of speed changes (ie, heavy stop and go traffic), a hybrid car is not for you. Buy a CDI/TDI diesel, or one of the lighter-weight Honda or Toyota econoboxes from 5-10 years ago. Just be aware, Hondas prior to 2000 or so have abysmal crash ratings (I don't know about Toyotas.) Use the money saved to switch over to energy efficient bulbs, install hot water solar collectors on your house, blow in insulation, buy new windows, etc.

Re:solar and hybrid myths

[qigong]

Use the money saved to switch over to energy efficient bulbs, install hot water solar collectors on your house, blow in insulation, buy new windows, etc.

You mean the energy efficient bulbs with all the mercury in them and that require a hazmat team to dispose of? Hmmm... I dunno.

You have some good ideas, though. Here are some more: How about turn off lights you don't need, adjust your thermostat a few degrees, check your tire pressure frequently, replace your appliances with the most energy efficient models, move close to work, bike instead of drive, use mass transit, do your laundry with cold water, put your computer to sleep when not in use, unplug chargers not in use, buy local produce...

Re:solar and hybrid myths

[Anonymous Coward]

I have to disagree.

I've checked into solar annually for the last five or six years and the numbers are not even close - even if you ignore battery maintenance.

While i'm eagerly following new developments like nano-solar's "printable" solar material (supposedly at least 1/10th of the cost and maybe cheaper-- plus lightweight and easy to install), you would be better served to put the cash in the bank ($35k to $50k of panels and gear for a typical house) and use the interest to lower your power bills.

Solar makes sense for areas where you would have to pay a lot of money to get electricity (cabins- pumps). Otherwise, it's a nice luxury... a nice hobby. And heck- I used to drop $2k a year on computers. You do that with solar for 17 years and you get "free" electricity after that where the computers would all be crap.

One plus for solar that most people do not consider is that the cost of power in absolute dollars roughly triples every 20 years. So if you put down $20,000 today (cash)- foregoing $1k a year in interest ($700 after taxes), and it generates $650 worth of power a year, that same power is going to cost you $1950 in 20 years. And you do not pay taxes on money you save- while you do pay taxes on money you earn.

If you have links that show how to hook up the typical 2k square foot house cost effectively, I'd like to see them. I've been interested in going solar for close to a decade but the math just never works so far. Of course, there are no rebates in my state and power is only $12.4c/kwh.

Re:solar and hybrid myths

[mcsqueak]

"Hondas prior to 2000 or so have abysmal crash ratings (I don't know about Toyotas.) Use the money saved to switch over to energy efficient bulbs, install hot water solar collectors on your house, blow in insulation, buy new windows, etc."

I survived a roll-over freeway crash in a 1983 Toyota Carolla. I was hit from behind by a semi truck in the left tail light area, which flipped my car around 180 degrees, then caused me to roll three times across the upper deck of a freeway bridge. I came to rest with my roof pressed against the guard-rail. I had my seatbelt on on walked away with a small scratch on my head (from glass I think), and some soreness in my shoulder. The car was totaled, but I was safe, thats all I can say about Toyotas. After the crash I went ahead and bought a new 07 Toyota with all the airbags and stuff.

Re:solar and hybrid myths

[terrymr]

There's probably more mercury in your teeth than in flourescent type lamps around your house.

Re:solar and hybrid myths

[SvnLyrBrto]

> You mean the energy efficient bulbs with all the mercury in them
> and that require a hazmat team to dispose of? Hmmm... I dunno.

On the way from my gym to the Transbay Terminal, where I catch my bus home every day, I walk past a place where one can drop off their used electronics (Yes, including those mercury-laden compact fluorescent bulbs.) for proper disposal and/or recycling. Next time I have a CF* bulb crap out on me, I don't think it'll be too much effort to stop in and drop it off in the appropriate bin. If that measly half-minute is too much of a detour for me, forking out a slightly larger initial investment and using LEDs for lighting is always an option.

( * It's been ages since I HAVE had one die. But when I moved into this house, I replaced all the regular bulbs with CFs in one go, so they're probably all due to fail together. But by the time that happens though, LED fixtures probably WILL have matured to a decent replacement price.)

So, thanks for the concern and all. But I think my present fluorescent bulbs are still a winning solution.

cya,
john

Re:solar and hybrid myths

[DerekLyons]

The math with current photovoltaics will not come out in favour until the fossil fuel rises by a factor of at least 10 times. Does not matter what, how, who, where. They are simply too expensive to provide a reasonable ROI. They also have a very high environmental cost to produce so people who buy them are not doing a lot of good to the environment.

This is a myth often repeated. I'm going to simply point to a google search that will net many informative results. You'll find numerous calculations which all come to similar conclusions: solar panels have an "energy payback" of a few months to a few years, and their warranties extend well beyond the point where they become a source of income for the owner.

Sure, I find many informative pages on the subject - all from people with a vested interest in convincing you that solar power is a good idea, (either because of their politics or because they want to sell the systems to you).

Re:solar and hybrid myths

[vk2]

I believe GP post is refering to this incident -
http://www.rickroot.com/blog/1/2007/04/CFL-Compact -Flourenscent-Lightbulbs--Are-They-Dangerous.cfm

Not sure if this is just a hoax or for real.
Loud mouth Neil Boortz mentioned this over his talk show yesterday.

Re:solar and hybrid myths

[Rogerborg]

Oooh, look at all those studies that say that investing in solar power firms is a good idea.

Now, can Google find a solar cell factory that uses its own products?

I'll wait while you search. Off you go.

Re:solar and hybrid myths

[sustik]

> Just be aware, Hondas prior to 2000 or so have abysmal crash ratings (I don't know about Toyotas.)

Honda Civic 1998 (I own one, and I just got a 2007):
http://www.carfax.com/car_safety/ratings/SRR.cfm/y ear/1998/make/HONDA/model/CIVIC/trim_id/1998HOND4D FCIVIC_LX

Toyota Corolla 1998:
http://www.carfax.com/car_safety/ratings/SRR.cfm/y ear/1998/make/TOYOTA/model/COROLLA

Chevrolet Cavallier 1998:
http://www.carfax.com/car_safety/ratings/SRR.cfm/y ear/1998/make/CHEVROLET/model/CAVALIER/trim_id/199 8CHEV4DFCAVALIER

I would call the Honda bellow average but not having abysmal ratings (the best of the above 3). Interesting that the Toyota has better Crashworthiness but worse "Injury, Collision, & Theft Indicators" than the Chevrolet.

Re:solar and hybrid myths

[nmos]

This is a myth often repeated. I'm going to simply point to a google search that will net many informative results. You'll find numerous calculations which all come to similar conclusions: solar panels have an "energy payback" of a few months to a few years

What a bunch of BS. Unless your talking about a remote site without grid power nearby there is just no way you're going to see a payback for a solar power system on the order of months. Even a few years is really stretching things except for very large values of "a few". I'm not saying solar electric isn't a good alternative but these kinds of exaggerations really don't help the cause.

Re:solar and hybrid myths

[Hoi Polloi]

Well what do you know, you are right...

Weight of a typical filling (3mm x 3mm): ~ ~0.025 g (50% Hg amalgam)
Amount of mercury in a standard fluorescent lamp: Avg ~ 20 mg but varies from 3-46 mg

Since most people have multiple fillings that is a minimal amount.

The Hg in lamps is in an elemental form and is metabolized in the environment into highly toxic methylmercury which accumulates in the food chain. Mercury amalgam slowly leaks into your mouth (approx 30 mcg/day/filling). Neither one sounds too great!

http://www.worldwise.com/recfluorlig.html
http://www.ibiblio.org/amalgam/

Re:solar and hybrid myths

[Damvan]

I think you misread his post. He was talking about the energy payback of the solar system, not the cost payback. Most modern panels produce the amount of energy it took to manufacture the panels themselves in a few months to a couple years. If you reread his post, and the portion you quoted above, he said "energy payback."

If you are calling BS on his point on energy payback, as simple google search will result in many sources confirming his assertation.

Re:solar and hybrid myths

[nmos]

Re-reading his post I think you may be right. I was certainly talking about economic payback, not energy payback.

Re:solar and hybrid myths

[amchugh]

From a tech standpoint you are right about freeway commuting in a hybrid, but CA offers HOV (Carpool) lane access to hybrids (if you got the sticker in time).

Re:solar and hybrid myths

[Anonymous Coward]

The total amount of mercury in one CFL is about the same as 40 cans of albacore tuna (no link...dig through the last story submission on CFL's...the link and math are there if you question). In other words, you could eat the lightbulb and still have less exposure than from eating mom's tuna caserole twice a week for a year (assuming 2 servings per can). I believe the mercury in some CFL's is also contained in a coating when turned off that helps prevent its release when the bulb is broken.

Re:solar and hybrid myths

[Hoi Polloi]

"I believe the mercury in some CFL's is also contained in a coating when turned off that helps prevent its release when the bulb is broken."

I thought the Hg had to be in vapour form for the UV emission process to work? The coating is just the phosphor.

I'd be sick of mom's tuna casserole LONG before I had 40 cans though!

Re:solar and hybrid myths

[blueskies]

I think he means the energy efficient bulbs with mercury that don't require a hazmat team to dispose of? The ones that use less energy so power plants don't have to release as much mercury into the atmosphere.

Time of Use Tariff is Great

[Calibax]

I don't know what is causing the drop-off. However, I do have solar energy system that was installed in 2003. I was not required to install a time of use meter (the E7 tariff in California) but I moved to that tariff because it makes great sense.

The normal baseline rate for electricity on the standard residential tariff (E1) is 11.4 cents/kWh rising to 36.4 cents/kWh for usage over 300% of baseline. On the E7 tariff, during summer peak time (noon to 6pm) the baseline cost is 29.4 cents/kWh rising to 52.8 cents/kWh for over 300% of baseline usage. However, off-peak cost is 8.6 cents/kWh to 32.1 cents/kWh at 300% usage.

What do all these numbers mean? My solar array generates a high percentage of the total amount of electricity generated during peak time. I know this because a data monitor was installed on my solar array and I have detailed numbers on the performance of the panels and inverters. I think it was well worth the $1500 additional cost.

Bottom line: last year I used 16,345 KWh of electricity, 12,096 kWh generated by the solar panels and 4,249 provided by the utility company. However, I ended the year $191 in credit with the utility. This is because they credit me at the current rate when I send electricity back into the grid, and I'm delivering electricity at the time when I get the highest credit, and I'm using electricity at night when the price is lowest. So, last year I received 4,249 kWh of electricity from the utility that I didn't have to pay for. Without the E7 tariff I would have received ~$1,200 less credit for peak time generation and I would have paid ~$160 more for the electricity I did use.

Obviously, mileage will vary for different installations. For me, time of use has been, and continues to be, a great financial benefit. It also contributes to home comfort: I sent my home thermostat to a minimum of 72 degrees and a maximum of 76 degrees, and that's how the thermostat stays 24/7 all year. Extravagant maybe, because I could have saved more electricity with different thermostat settings, but I like my comfort. And saving electricity doesn't do me any good because all it gives me is a larger credit with the utility company (and I can't convert that to cash).

Re:Time of Use Tariff is Great

[mdsolar]

I think what is happening is that folks with smaller roofs are seeing a problem. Your system is large enough so that it does more than you use during peak so you actually get a credit at the higher rate. If you are only supplementing your use during peak then you have to pay at a higher rate because (in CA) you are forced into the TOU contract.
--
Get the right sized system that stays the right size: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Re:Time of Use Tariff is Great

[cweber]

You are absolutely right, TOU billing should work to the advantage of most consumers, and if it doesn't there are underlying issues which need to be addressed. As you rightly point out, PV system produce the most energy during peak hours. The largest energy uses in many CA homes are for AC during the summer and items such as pool pump, as another poster stated. Both uses are typically highest during peak pricing hours, but they can be avoided or engineered around, as has been pointed out, or at least moved to off-peak hours. But more fundamentally, these uses represent elective luxury items and aren't strictly necessary at all. I'm taking a fairly lax view of "necessary" and factor most appliances, such as refrigerator, TV, etc. into it, but the pool does definitely not qualify, and cooling in summer shouldn't be necessary in a properly constructed and insulated house in coastal areas such as Rancho Palos Verdes as quoted in TFA.

As such, if a home's roof doesn't have enough area to allow for a PV system to cover most or all of the net electricity needs, then a home owner needs to critically look at electricity uses and rectify the situation BEFORE a PV system goes in. And PV installers should learn to collaborate with energy consultants, insulation installers and others in order to provide more complete and appropriate solutions.

If you yourself can break even with less than 100% PV electricity capacity while hitting the 300% of baseline usage price bracket AND using AC 24/7, then anyone should be able to as well.

Re:Time of Use Tariff is Great

[Damvan]

If you don't mind me asking, what data monitor did you have installed with your system? I would love to have access to that kind of performance data. I have a Sunny Boy 2500u inverter.

Re:Time of Use Tariff is Great

[Calibax]

I have 48 x 185 watt panels connected to three Sunny Boy 2500u inverters which are connected to a Sunny Boy Control using RS422. The Sunny Boy Control is connected to a PC using an RS232 serial line.

The Sunny Boy Control is set to collect data from the inverters every 5 minutes. It stores AC power generated at that instant, cumulated AC power generated that day, DC voltage and current into each inverter from the panels, AC current out, any errors that turn up, and some other useful and useless information. I have an automated task to dump the data from the Sunny Boy Control into the PC daily.

Re:Time of Use Tariff is Great

[Damvan]

Thanks for the information. I will look into the Sunny Boy Control. Presently I am simply taking down the data manually once a day from the display on the inverter.

Re:The math will never come out with current panel

[vtcodger]

FYI -- The US had a similar solar boiler -- 10MW -- at Yermo, CA just East of Barstow in the 1980s and 1990s. I doubt the economics are that great. (plant only works when the sun is well up, there aren't too many clouds, and the wind isn't blowing too much dust around). Otherwise, there would have been follow-ons and commercial projects. Maybe with today's higher electric rates ... But probably not.

I'm sure that there is an in depth analysis of Solar 1, and Solar 2 -- the Yermo facility -- around somewhere, but I didn't have time to look it up. Got stuff that needs to be done -- now.

Re:"CA" is a postal zone....

[eln]

Aren't they both Federal bureaucratic inventions?

Largely down to inefficient AC systems

[Colin Smith]

In hot areas.

i.e.

Poor insulation.

Partially mirrored double/triple glazing, double walled roofs with an air gap, glass wool thermal insulation in the ceiling and between walls and cavity wall insulation on external walls.

Then of course they also usually expel the heat into the air rather than storing it underground. Think heat pump. You pump the heat out into the ground outside during the day and suck it back in for space/water heating in the evenings. A heat pump can be 400% efficient or so, so if you power it from the solar cells you can effectively quadruple the effective generating power of the cells.

Re:Largely down to inefficient AC systems

[Dun Malg]

A heat pump can be 400% efficient or so, so if you power it from the solar cells you can effectively quadruple the effective generating power of the cells. Errr.... anything beyond 100% efficiency is a perpetual motion machine. 400% efficiency is a felony violation of the 1st and 2nd laws of thermodynamics.

Net Metering and your numbers...

[nweaver]

A question: Do they still have net metering available (meter runs backwards if you overproduce)?

If so, does the net metering also respect the differential pricing?

This might actually be really useful then, as if you overbuild by 2x, those extra 4kW would be generated during the peak-price time.

Re:Net Metering and your numbers...

[bcrowell]

A question: Do they still have net metering available (meter runs backwards if you overproduce)?
Yes, but they will never write you a check. They put you on yearly billing, and the best you can do is to zero out your bill at the end of the year. If you overproduce, they take the excess energy you produce, and don't pay you for it. Because of that, nobody builds a grid-tied system that overproduces.

This might actually be really useful then, as if you overbuild by 2x, those extra 4kW would be generated during the peak-price time.
It's true that the new TOU requirement has the effect of providing a very strong incentive to build the biggest possible system. However, you can't get paid for overproducing. In any case, people generally don't have enough roof space to be able to build a system that has overcapacity.

Re:Net Metering and your numbers...

[mdsolar]

From the freak.... We're finding for our customers that under TOU, a ~60% system is about optimal. This is because we charge a flat rate. You are seeing actual savings from your intended purchase so that is a positive though as you say it is not as attractive as a bond investment. For others, it might make sense to rent until a purchase can actually equal or exceed a bond investment. Panel prices will be coming down as the solar grade silicon supply improves so waiting to purchase might make some sense. You can see rates for renting by following the links at http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

VRLA-AGM, and nothing else!

[Gazzonyx]

And for craps sake, people, make sure it's a VRLA-AGM. If you're charging these things and it's not this type, which recombines the hydrogen... well, don't "flic your bic", or you'll become an artificial satellite for a good few seconds!

I've got one for my backup server, it cost me like $300 at a boat accessories store. 89 AH and it runs for hours (something like 10 on a fairly power hungry old skool Athlon TBird, or something to the effect - might be a duron, come to think of it). Oh, and watch out for thermal runaway during charging, or you won't have to light a smoke to be toasted.

More Info:
Deep Cycle Battery FAQ

Re:VRLA-AGM, and nothing else!

[Gordonjcp]

Or, you could make sure it's somewhere well-ventilated. They need to be kept warm, though. Not hot - just warm. You'd be amazed how much the output of a cold battery falls off. In fact, in old Lada owner's manuals, they recommended that when it was very cold, you turned on the headlights for a couple of minutes before starting. Why? Because the lights pull down a fairly restrained 10A from the battery, which is enough current that its own internal resistance will cause it to heat up. Once it's warmed up a little, it will be far better at delivering the 200A or so that the starter will need...

Re:VRLA-AGM, and nothing else!

[Gazzonyx]

Right, in my situation in a server rack hidden from my landlord and roomies, ventilation wasn't much of an option. Your personal options may vary, but err on the side of caution, please! Just remember, hydrogen becomes explosive (well, flammable, explosive if contained) at concetrations > 4%; while in a large room this takes hours, but it also means being at work all day with a bubbling over battery could be a problem. I calculated if my AGM vented (it can to prevent thermal runaway, but vents < 1% of 'wet' batteries at full open valve), it would become dangerous in my closet in around 8 hours not taking into account all the fans inside to stay on the safe side. But if you're floating it correctly (add ~.5 volts, I think... double check this number), you shouldn't be gassing too much.

And, right you are on the tempature thing from the link I posted:

Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up. This is why your car battery dies on a cold winter morning, even though it worked fine the previous afternoon. If your batteries spend part of the year shivering in the cold, the reduced capacity has to be taken into account when sizing the system batteries. The standard rating for batteries is at room temperature - 25 degrees C (about 77 F). At approximately -22 degrees F (-27 C), battery AH capacity drops to 50%. At freezing, capacity is reduced by 20%. Capacity is increased at higher temperatures - at 122 degrees F, battery capacity would be about 12% higher.

Solar Thermal

[rohar]

Concentrated Solar Thermal plants are an established technology. The heliostat central tower design is very interesting, the video from BBC is worth watching. Vinod Khosla is investing in a flat mirror idea, there is video of the system and an interview with Khosla.

The SEGS plants at Kramer Junction in the Mojave Desert have been operating since the 1980's and are the largest solar plants in the world producing 354 MW.

Nevada Solar One is 64MW of solar thermal (3rd largest solar plant) and set to come online this year.

Stirling Energy Systems has a CPUC approved contract with SCE for a 500MW parabolic stirling solar thermal plant.

This document details a lot of the 100 year history of solar thermal attempts.

SHPEGS is our not-for-profit design project to adapt solar thermal to moderate climates by combining it with geothermal and heat pump technology. There is more information and links here.

Re:Solar Thermal

[arivanov]

Thanks, lots of really good links. The Kramer Junction has miles and miles of pipework with associated heat losses to transport across it. It is impressive, but IMO it is a detour into a dead end as far as reducing costs of solar energy is concerned.
What sets the Spanish project apart is as you pointed out the heliostat design. Cheap, cheerfull and very simple to build with modern technology. Compared to Kramer junction these can be built by the dozen in nearly no time at all. In fact it can be done with simple flat mirrors to reduce costs. So much for the Archimedes mirror being useless and unable to heat up anything (as per Mythbusters).

Re:Solar Thermal

[rohar]

Solar Two (not the same as Nevada Solar Two) was a heliostat central tower design. The flat mirror fresnel idea that Khosla is investing in is between the two ideas. Rather than a solar trough, flat strip mirror heliostats are at ground level with the receiver pipes above.

Re:Solar Thermal

[arivanov]

Haha, they seem to be relatives. The Spanish is in fact a commercialisation of Solar Dos.

Anyway, that is a plant which I do not mind having in my own town.

Everything else aside it is damn pretty. Looks like a cathedral. In fact it will not look that much out of place next to Sagrada Familia or any other post-modernist cathedral.

Figures that CA can mess up solar

[Anonymous Coward]

I wonder sometimes if the state of CA, pretending to be green and passing feel good laws periodically, which just raise the cost of everything for people living there, is really just a shill for whatever corporation is sponsoring it. Barring that, if a company isn't wanting a law, pass some useless and poorly written bill to appease the hippies once in a while.

Yes, pass gun laws, watch crime double, as the crooks still pack their Glocks and laugh at the citizens who can't fire back. Yes, keep taxes going where one can live in another nearby state, only have to make 2/3 as much to have the same standard of living, factoring out the bloated pyramid scheme of the real estate market.

California should just have the elections for governor and the other state lawmaking offices done by highest bidder in an auction and drop the pretenses of having anything to do for the subjects^H^H^H^H^H^H^Hcitizens. Yes, CA is a green state. Greenbacks are what give the orders there.

Re:Figures that CA can mess up solar

[Anonymous Coward]

The level of brainwashing your poor country has been subjected to ever since the "what, you mean we need to pay taxes to expect the government to help us fight the natives?" moment is astounding.

Now I don't wonder aGoogle datacenter is coming...

[AtariDatacenter]

From my last electric bill...

Actual energy cost per KWH $0.07

It was at $0.06 before the energy prices started going up, and at the peak of last summer, it climbed all the way up to $0.09 per KWH. (Fuel rate was 0.010 per KWH.)

I have no idea how you people manage to pay double or triple those costs.

Re:The math will never come out with current panel

[Firethorn]

With the tax credit -Key words here. In other words you're receiving a subsidy because you're not economic.

Back of hand calcs-
15k miles a year.
30mpg 'standard': 500 gallons fuel
50mpg 'hybrid': 300 gallons fuel.

Difference: 200 gallons. $600-800 in fuel.

Cost of a hybrid over standard: $7k (Honda Civic Sedan vs Civic Sedan Hybrid, base MSRP)

Break even point, assuming 0% interest? ~10 years. I usually assume a car's lifespan at 10 years. Many last longer, but many die earlier. Then there's the question of taxes and insurance. A car that costs 7K more is going to cost more to insure, and frequently cost more to license.

Solars tend to make up for their cost within 5 years(depending on location).

Last time I figured out for me(last year), it exceeded 40 years without figuring out cost of capital costs. I could actually take the money required, invest it into a mutual fund and more than pay for my electricity bills off of the interest alone.

Of course, I live in about the worst area for alternative power: extremely cheap local power($.08/kwh), combined with far north. I'd be better off going with wind. I've looked into a wind turbine before, but they don't have good figures.

Canada or California?

[vrmlguy]

Was i the only person momentarily confused by the title? Or does everyone think that California has .ca as its own TLD?

Re:Canada or California?

[John Bayko]

CA is the postal code for California, and has been for a long time. FYI, I live in SK.

Re:The math will never come out with current panel

[Anonymous Coward]

The math with current photovoltaics will not come out in favour until the fossil fuel rises by a factor of at least 10 times.

Good point, but not entirely accurate: 50% of the cost of electricity are the overhead costs involved in getting it from a generator to your house (including the administrative costs of your power firm). For solar cells installed in homes, the price difference is only 5x (you'll notice a lot of slashdot headlines claiming 5x more efficient solar cells: this is not necessarily because the claim is true, but more so because if it was true, solar cells would be cost-competitive with fossil-fuel based electricity).

Also, this last point brings up another point: fossil fuel doesn't need to face a 5x price rise, but there needs to be a combination of a rise in fossil fuel price and drop in solar cell price which give an overall 5x improvement in solar cell cost effectiveness. This is important. Right now, the solar cell industry is supply-constrained. The main ingredient in solar cells is crystal silicon, and there isn't enough crystal silicon to go around. If demand exceeds supply... well you took Econ 101. Right now, the crystal silicon industry is expanding like mad to fulfil the demand requirements of the solar industry. When this is worked out, prices of solar cells will drop dramatically. The CEO of Sharp, the dominant solar cell manufacturer, predicts prices will halve by 2010.

In addition to improvements in crystal silicon, there are all kinds of improvements in the pipelines. "Thin-film" silicon-based solar cells are becoming more common, and Sharp predicts they will soon become dominant. There are all kinds of process improvements used in produce IC silicon which could be used in solar silicon, but haven't yet been explored because the solar industry is so small. On top of that, there are many "pie-in-the-sky" approaches the solar cells (the 5x improvements you hear about on Slashdot every so often), which use materials other than silicon (like the still-difficult-to-mass-produce CiGS approach of Nanosolar), or using polymers instead of crystals (which are still way behind silicon in conversion efficiency). Again the CEO of Sharp expects a 4x improvement in solar cell efficiency by 2020, but I think he's being conservative.

Even if we accept his estimate, this means the price of fossil fuel only has to increase by 20% by 2020 -- not 5x and by no means 10x -- and a bigger increase would make fossil fuels hugely uncompetitive. Now take a look at what's happened to the price of fossil fuels since 1998. What happened? Massive economic growth in developing countries, especially China. Now, is it so hard to imagine this growth won't continue (on some pace, on average) through to 2020? What effect will it have on fossil fuel prices? I'm not saying they will go up by 5x -- actually, my point is the opposite: you have to look at solar cell efficiency, too, and I think within 13 years it isn't so offbase that home-based solar cells won't be competitive with fossil fuels for electricity generation.

Re:The math will never come out with current panel

[CreatureComfort]

Actually, the tech is originally American and has been in operation since 1981.

Re:The math will never come out with current panel

[Monoman]

So if everyone is smart enough to buy used then what happens? Will it drive down the price of new products?

For now the used market relies on these "morons".

Re:The math will never come out with current panel

[bcrowell]

The math with current photovoltaics will not come out in favour until the fossil fuel rises by a factor of at least 10 times.
Well, no. You simply have no idea what you're talking about. I've got a quote for a system sitting here in front of me. The return on investment is about 5% annually. Not great, but on the same order of magnitude as other relatively non-variable investments. If the cost of electricity rose by a factor of 10, then the return on investment would be 50% annually. If that day came, then everybody would go photovoltaic, even people in Anchorage with houses shaded by trees, and the electric company would go out of business.

Re:The math will never come out with current panel

[MrSteve007]

You're comparing the price of a base civic (manual trans, windows, etc) with a decked out hybrid version, with navigation, sunroof, power everything. Compare apples to apples, a Civic EX and the hybrid version, and you'll come out with a price difference closer to $2k. Using the above math, it'll pay off a little over 2 years. Sounds like good sense to me.

Solar Thermal pays for itself in a few years

[Colin Smith]

3-5 on average.

Don't bother with the electrical side, look at what you use the energy for. In general, it's

1: Air Conditioning in hot countries.
2: Space heating.
3: Water heating.

So instead, use the heat directly. Solar thermal panels are about 80% efficient, which is many times better than photovoltaic. You use a heat pump rather than conventional AC to provide space cooling. Move the heat around instead of generating it.

BTW, instead of pumping the heat used for generation out into the sea, they could supply it to a District Heating network and up the efficiency of the plant from 30% to around 85%.

There are no rebates for people off the grid

[kingduct]

Not only are people on the electric grid not being appropriately encouraged to use solar power, but people off the grid are in even worse shape. You get no rebates whatsoever if you are in rural areas where there is no electricity -- essentially meaning you should stick to a gasoline generator.

Sometimes I hope that if gasoline gets expensive enough it will cause people to get so upset that politicians will have to change their policy when it comes to energy. After all, I just read today that Condi Rice was on Chevron's board even as Chevron was giving kickbacks to Saddam Hussein to get Iraqi Oil. So, that means that she was contributing to a "rogue state" even as she was forming plans to overthrow it. Since then of course, we have a failed war and record oil company profits.

There will be no serious attempt to change our energy policies until we force it.

Re:The math will never come out with current panel

[elrous0]

Wait until you see the smile on the mechanics' face when he sees YOU pull in.

The terminator got it just right.

[raehl]

The rebate is to promote energy efficiency. As has been stated above, part of making solar power work is modifying how much energy you consume through things like LED bulbs and better insulation etc. And the people who do that should get the rebate.

If, when you install solar power, you find that it's not making financial sense for you because you still use a bunch of peak-time power, your solar power 'solution' probably isn't very good, and you're exactly the kind of person the government should NOT be giving a rebate to.

It's a great way to make sure people arn't just gaming the system. Just because the number of applications for rebates has gone down doesn't mean that GOOD solar power adoption has gone down - it could very well just mean that giving away government money for little or no useful impact has been reduced.

Re:The terminator got it just right.

[Anonymous Coward]

What you and others seem to miss is that according to the article the California PUC (Public Utilities Commission) has forceably set the rates to all new solar installation at peak rates regardless of the time of day they purchase the electricity to supplement their systems, regardless if it is purchased at night and battery stored or not. This effectively makes it to where anyone with solar that still needs some grid electricity have to pay extremely high rates for that electricity and thus reduces the economic performance of their system. If this was not the case then any peak electricity the customer generated via solar would reduce their peak costs and could make it worthwhile for a customer to slowly add solar as they could afford it however this PUC decision makes it only worthwhile to put in solar if you put in a system that takes you completely off the grid from day one. According to the article, there has been no new solar in California since January 1 "GOOD" or otherwise.

SAY WHAT?

[wilder_card]

>>Edison charges summer time-of-use rates that range from 29.7 to 35.9 cents per kilowatt-hour between 10 a.m. and 6 p.m.

Here in VA we're paying 6.52 cents/kilowatt-hour. No wonder there have been charges of price-fixing and gouging. Holy crow.

Re:The math will never come out with current panel

[Lumpy]

Not completely, most of my used panels are from companies or even the big solar plant out there in Arizona. Almost none of the used panels on the market are removals from homes.

Re:The math will never come out with current panel

[inviolet]

Why are hybrids a gimmick? With the tax credit most hybrids pay for themselves within a year, although some people who drive less it takes up to one and a half years. Only new, not used. And fossil fuel infrastructure has a huge enviromental cost to produce and solar panels are easily winning that war. Nothings perfect, and as we go forward you won't be energy neutral because energy is what we need, but setting in stone the things now is good.

I can't tell from your post whether or not you have realized this, so I'll say it and then beg your indulgence if you already knew it...

A tax credit is simply a transfer payment (but less honest). If tax credits are required in order to make hybrids break-even, then hybrids are actually lossy in the total social sense. Owners of hybrids are in-the-black thanks only to a fraudulent subsidy from their neighbors.

That said, there are some who argue that the tax credit for hybrids is functioning as a carbon tax on owners of non-hybrid cars. And there's some merit to that, qua the (questionable) basis of carbon controls. But this is probably more discussion than you wanted.

Messed up Rate structure

[aero6dof]

The point of the LA Times article, I think, was somewhat missed. The rules that the California PUC elected to pass force CA solar rebate applicants to use a different rate structure from regular residential customers. Apparently no one on the PUC closely reviewed the math for the change. As a result, solar installs that only partially replace daytime electricity use often (always?) result in higher electricity costs to the homeowner - even figuring in the rebate.

This pushes the economics of the proposal out of the realm of many forward-looking customers willing to accept a medium to large capital investment with a small, long-term rate of return. Instead, the rules require a huge capital investment (for a typical homeowner) for the same small, long-term return, or a small/medium investment resulting in long term loss. An interesting side observation out of this is that almost all people considering solar PV systems were capable of performing the math to make the assessment - something that is a don't know or don't care issue for the general public.

It's interesting to note that the CA PUC initially wanted to give most of the solar rebate allocation to big utilities before being stopped by the governor. No doubt allocating it to utilities would have resulted in technologically higher efficiency installations - but I suspect directing rebates to residential users puts both more wattage online overall, as well as in a shorter timeframe. This latest mistake makes me think the PUC is just continuing it's previous direction - if no one had noticed, there would have been a big pot of money left near the end of the program which probably would have been redirected toward utilities again..

Re:Messed up Rate structure

[mdsolar]

I liked that too about the article, people are doing their own math and it is not that hard to do. I also agree that putting panels on residential roof gives more power than commercial roofs though both should be happening. Your analysis of the PUC is interesting: the fox's lap dog is guarding the hen house?
--
Renting solar power works well under TOU: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Heaviest users of oil are passenger cars

[NeutronCowboy]

I agree with your points, but I would like to point out that passenger cars account for 40% of our oil use in 2004. The link is from a tree hugger site, but it references the Annual Energy Information Administration Annual Assessment from 2004. This was on the first page of a quick google search. Considering that the EIA estimates that 2/3 of all oil use in the US is for transportation, and 2/3 of that oil is gasoline, I'd say that the 40% number quoted by the site is pretty accurate.

So yes, lowering gas consumption of passenger cars by even 5% would have a noticeable impact on the US oil consumption. Doubling the gas mileage would reduce our oil useage by 20%.... something to think about.

Idea Just thinking outloud

[Archangel Michael]

How about doing a comparison of buying electric power to store in batteries during off-peak hours, and using full battery + solar for daytime usage during Peak hours. I'm not sure of the efficiencies of converting power to and from battery vs the cost of buying off-peak power and storing it until you need it during the day.

The idea here is to use Solar as a boost to battery power during the day, and using lower cost electricity to charge the batteries during the night. I think the whole thinking of using Solar and standard power during the day by itself is futile, at least using the conversion rates of solar, and the cost of the higher peak use electricity costs.

Someone with better knowledge of the conversion % loss and Electric Rates can do the math to see if this is actually better alternative ....

About Edison's Dirty Little Secret

[LifesABeach]

As a home owner in Orange County California, I think it might be a good thing if Edison started working with Home Owners. Currently, Edison's position on helping OC-Homers is like being a victim of a "Bronks Cheer". I would hope that Edison changes their corporate position on this contemporary issue. Let us face the undeniable reality, "Brown Outs" are NOT caused by an over abundance of Electrical Power Available. And a simple observation of roofs in the OC using Google Earth, shows more residential roofs, than commercial roofs. I believe that if Edison had a choice of either obsorbing the cost of avoiding Brown Outs, or help putting Solar Panels on Residential Roofs; That the prices of Solar Power would come down quickly.

Re:About Edison's Dirty Little Secret

[Locutus]

the problem arises when PV pricing starts getting to the point where an enterprising resident can become a power plant and make some money selling peak power electricity. But, the utilities already have roadblocks put in place to help keep those interested in clean energy production down in the noise levels. My guess is that they would rather have brownouts and still make massive profits then to start letting alternative generation systems slowly start taking aways their profits by reducing demand.

Think about it. The energy companies already know that by strategically timing maintenance of critical generation systems, they can reduce supply and boost profits. It was done in 2000 by the electrical generators, mostly in Texas, and currently it looks like the oil industry might be doing the same to help run gasoline prices up.

I've heard a number of people complain about current regulation and utility policies are blocking the increased use of solar PV energy generation so it's not surprising to here any of the TOU issues coming up now. They are looking out for themselves and the PUC seem to be oblivious to any of this.

LoB

Re:About Edison's Dirty Little Secret

[Khashishi]

Can't the energy companies just charge more for energy than they are buying for? They'll evolve into more of a energy broker system than pure energy production.

Locational Marginal Pricing Map

[dj245]

Price is capped at $1000 per MW*Hr. Comes out to about $1 per KWh. Date was August 8 2006. Every plant ran and Foxwoods went off grid to help out. Some businesses sent people home. This year could be bad since even more people have AC systems and more grid capacity hasn't really been installed.

Re:Batteries-already done

[Anonymous Coward]

Instead of speculating, how about using google to see the thousands and thousands of installations where they DO use battery banks for homes? It's doable. It just is. People spending half a million to a million bucks on a house in California can afford 40 grand for a very sophisticated rig, and tie it directly into their long term mortgage, then they got their electric bill covered for 25 years + with no sudden sticker shock price increases, along with peace of mind that they won't be suffering "rolling blackouts" or whatnot. Added bonus, up the size from there and when electric vehicles become common at the dealers- within two or three years now-you'll have your transportation costs covered for most purposes as well. And you can still keep the system grid tied to boot if you want to use the grid as the redundant backup, instead of vice versa, and slap it on a timer so you only use it at the lowest rates times. And people don't need any more incentive or financing than that.

Enough with the FUD, solar PV works NOW in huge numbers of places for a lot of people. Not for everyone, but for millions it is perfectly viable as long as you just get rid of that short term thinking. How long you want to live in a house? Think that way and it makes sense, and the damn housing bubble popping should also make it sink in that your house is YOUR HOME to live in, not some damn stock for pump and dump schemes.. Overseas they can't build the damn factories fast enough because of the demand, BECAUSE IT WORKS RIGHT NOW. With solar PV you eventually break even then start making good profit, that part varies widely but it's true, but with grid-only, IT NEVER HAPPENS, NEVER, there is NO "ROI' with grid supplied electricity, so compare THAT. with grid only you'll pay through the nose forever, with your rates always going up, with no control over them, because you have no long term pricing contract, nor will the fatcat energy cartels sell you one. So much for "regulations", where's the regulation that will allow you to demand something more than a freaking month by month electricity rent scam from your local utility?

Unless you are someone who rents everything they use, and think that is just ducky, it is a much better deal to OWN STUFF outright. It's called "building equity" and is taught in econo 101. Owning your own power is enabling, being 100% dependent for it, something as damn necessary for modern homes as it is, is foolish long term economics and even worse for guaranteed "uptime". You want your computers to have good uptime, including a UPS system, why not your home? A solar PV rig with a good battery bank is a WHOLE HOUSE UPS system that guarantees some good uptime. A home without power due to weird geopolitics and sudden gotchas in the world energy markets or some natural disaster goes from affordable and good enough to OMG THIS SUCKS. Egads, read the damn news sometime. How many energy costs sudden increases does it take to sink in? How many natural disasters where the grid goes down for weeks or months does it take to sink in? The 20th century was the big push for centralized, massively controlled and profitable for the fatcats distributed power, the 21st century is the era of DECENTRALIZED power, based on solar and the wind and geothermal and hydro. Adapt and adopt or stay at the fatcats and moms nature's mercy, two choices. Why the HELL you still want to keep making energy cartel billionaires even richer is beyond me, why the hell you want to 100% rely on the grid when it has been proven over and over again how fragile it is, especially in emergencies when you really NEED power is beyond me..

that's exactly...

[zogger]

..what a lot of folks with solar systems do. They try to keep the battery banks topped off, plus run their heavy usage stuff in mid day. If they need additional from the grid they pull it in at nighttime and try to get cheaper rates then.

With solar you have to work both ways-keep trying to drop demand,(insulate way beyond normal, get only ultra energy efficient appliances, be sane about turning things on and off, etc) as you add to your own production (solar scales, you can start smallish and add to it as you can). Eventually those two lines would cross on a graph and you have become energy independent.

Depends on where you are

[Flying pig]

There are places where hydro will be cheapest, certainly, but in fact there is a hidden cost as with nuclear. This is the lost opportunity cost of the land that is flooded to create the reservoirs that are normally required. When the population was lower this was less important, but I believe that a number of smaller dams are being removed because, taking all opportunity costs into account (tourism from restored rivers, land reclaim, cost of desilting reservoirs to keep hydro working) the hydro power they produced was no longer economic.

Fortunately reclaim takes a relatively short time (10-40 years) compared to dealing with nuclear waste products.

Of course, if China had to meet Western environmental standards for their coal stations, the economic miracle would be suffering a hefty dose of atheism by now.

Re:Depends on where you are

[LWATCDR]

Yes yes nothing is free. I am talking just about accounting dollars. Hidden costs are often overblown to the point of fantasy. One person I know tried to tell me that than more oil was used in building a nuclear plant than was saved by one.

Dams are interesting because while they destroy one type of ecosystem they create a new one. A river valley is turned into a lake. Which is a better ecosystem really depends on who you are. Yes Dams have an impact but each location is different. In some places putting a dam is a really bad idea. In others a good one.

Frankly I would rather deal with the impact of a western nuclear plant more than any Coal or Oil fired plant. In fact I live with one in my town so it is in my back yard :)

Really POORLY written article

[gurps_npc]

The basic claim seems to be that by requiring solar buyers to use per hour rates, it somehow drives the cost of electricity up.

But solar power is itself most usefull during the hours when the rates are HIGHER - because usually that is noon, when air conditioning is requiried, and also when the sun is brighter. Therefore your savings should be greater, not less.

For this article to be true, then one of three things must be true:

A. The utilities are charging them higher rates, but are not paying the same higher rates for electricitrity the utilities buy from the home owner.

B. The utilities have in some way 'cheated' the customers using the 'hourly rates', rather severely.

C. The article has made major errors, and the hourly rates have nothing to do with the issue.

Re:Really POORLY written article

[Control Group]

You're assuming the solar array more than covers the house's peak load. I think the point is that, in many instances, it doesn't. So homeowners are still paying for power from the grid during peak, and the requirement to go to TOU metering ups the rates such that they're still paying roughly the same out of pocket as they were before installing solar.

They're still buying less power, of course, but if that doesn't get reflected in the bill, then it's cold comfort at best.

Re:Really POORLY written article

[gurps_npc]

No I am not, you are failing to understand the math. Even if you just reduce the peak load, that is enough. Why? Because your are reducing your use of electricity at the high price, while still using pretty much the same electricity at night, during the lower prices.

Look the "peak/off peak" system is NOT a way to screw the customers. It is supposed to average out the same total cost for the entire year. That is, without the solar power deal, using "Peak/Off Peak" should mean higher electrical prices in the summer but lower prices in the winter (as electricity, unlike oil/gas is cheap in the winter).

With the solar power deal, the worst case scenario should be that during the summer they pay the same as they would normally without any reduction or increase but during the winter, they still get the same lower prices. So they end up saving money over the year, just all the savings are during the winter instead of spread out over the summer.

As long as the Utilitiy is doing the Peak/Off Peak thing in a fair/reasonable manner, it should NOT increase total cost, but should decrease total cost.

NUCLEAR...

[Notquitecajun]

What is most interesting about this thread is the dearth of the discussion of nuclear power.

It's cleaner, safer, and just as or more efficient than anything else out there, but there are FAR too many people who got scared by Chernobyl and Three Mile Island 30 years ago to form a reasonable opinion about modern nuclear power.

My understanding is that the book that Al Gore based his movie off of (which I didn't see) addressed nuclear power, but he didn't....probably because if we had it, he wouldn't make so much money off of carbon credits.

Re:NUCLEAR...

[paleo2002]

Seconded. People are scared to death of nuclear power due to lack of education and crumbling infrastructure. Out here in NY/NJ we're always hearing about malfunctions and break-downs at Indian Point. The plant, like many others in the US, is more than 30 years old. Surely a new nuclear plant built with modern materials, technology, and monitoring systems would be safer and more reliable. Yes, nuclear waste is a serious issue. But, maybe if the Pentagon allowed us to recycle nuclear fuel rods like they do in France and elsewhere, the problem would be less severe.

Not just a failure of economics...

[w3woody]

Here in Southern California property prices have gone up so much that springing a few grand for a roof-mounted solar panel system, even if it doesn't quite pay for itself for a few years, would be an easy thing to do. And with the amount of tree-hugging liberals here in Lala land, even if it doesn't pay for itself, the fact that you can claim to your friends that you're got solar panels would be enough to buy them. So economics by itself isn't a problem here.

There are two additional problems. First, in many municipalities (such as here in northern Glendale), there are restrictions on the equipment you are permitted to mount to the roof. Roof-mounted air conditioners are against the building code: they're considered an eye sore. If you're not permitted to mount a small box on your roof, you sure as hell aren't going to be allowed to mount a thousand square feet of solar panels to your roof.

The second problem is that many of the homes built throughout areas like Glendale were built in the 1930's--the roofs were constructed using 2x4 beams and simply will not support the additional static load. Many roofs on older homes are also not flat, but have a slight depression to them that would be exaggerated by adding additional static load. To add solar panels to my home, for example, I would pretty much have to rebuild the entire roof of my house, replacing the 2x4 beams with load-bearing trusses. Suddenly what was supposed to be a fairly simple multi-thousand dollar project has turned into a royal pain in the ass multi-tens of thousands project.

Re:Not just a failure of economics...

[Damvan]

The "Solar Rights Act" of California, passed in 1979, protects your rights to solar access. The City of Glendale, per this law, cannot prevent you from installing solar panels.

"California Civil Code 714

Prohibits local governments from creating unreasonable barriers for solar energy installations. Additionally, any reasonable restrictions cannot cost more than $2,000 and cannot reduce the efficiency of the solar energy system.

California Health & Safety Code 17959.1

Prevents cities and counties from denying solar energy system installation permits unless there is substantial recorded evidence that it would have a specific, adverse impact on public health and safety."

Mod parent up.

[Animats]

That has it right. The rate structure was set up in a way such that you don't make money off the solar panels unless you have enough of them to cover your peak daytime load.

This actually makes sense. It encourages people to install enough panels, keeping this from being merely symbolic. The problem is that, with current panel costs, efficiencies, and roof space, installing enough panels to cover the peak daytime load is tough.

Maybe, rather than focusing on houses, this should be targeted to flat-roofed commercial and industrial buildings. There's no reason that most of the roof space of a mall can't be covered with racks of angled solar panels, enough to power the air conditioning load.

That should really be the goal for California - power the peak air conditioning load of Southern California entirely from solar power.

Re:Now I don't wonder aGoogle datacenter is coming

[AaronW]

You have no idea how lucky you are. It is not unusual for me to hit $0.34/kwh where I live. One reason the rates are so high is much of the power generation in California is natural gas, which has become increasingly expensive. I have friends who have power bills hitting over $2000/month! One of them installed a 6KWh solar array which made big difference and the other is also considering solar. My bill only hits $150-$250 per month. A side effect of this and building requirements put in place since the 1970s have resulted in California using about 60% of electricity per capita as the rest of the country as well as the amount of electricity per capita remaining nearly constant since the 1970s (CO2 production is actually about 30% less).

One reason it's so expensive here is much of the electricity is generated by natural gas, which has become very expensive in recent years. I would love to see more nuclear power plants built in the state (as well as breeder reactors to deal with the waste). Solar helps, but won't solve all the needs.

Missing Option

[Anonymous Coward]

Power from sunlight? I live in my mom's basement, you insensitive clod!

I'm a skinflint who likes manual transmissions

[Firethorn]

Yeah, but I don't need all the power stuff. Besides, the basic honda civic is rated closer to 34mpg than 30mpg, and I happen to like manual transmissions. Oddly enough, the current automatic transmission is rated for better milage than the manual, by 1mpg, but costs a little more. The models I compared do NOT have satellite navigation, and investigation shows that even the basic civic has power windows and such today. Whatever... ($800@$3/gallon=266 gallons, or around 9k miles)

Still, more detailed comparison.

Civic Hybrid: 50mpg*, Base MSRP(NO SatNav) $22.6K, 5yr maint: $2,056
Civic LX: 34mpg, MSRP: $17K, 5yr maint; $2,011

Accessories on the Hybrid but not on the LX: Automatic Climate Control and Satellite radio. Let's say the missing features are worth $2k, so it's 22.6K vs 19K. Difference of $3.6K.

15k miles:
Hybrid: 300 gallons of fuel
Lx: 441 gallons

Difference: 141 gallons of fuel, $423@$3/gal. $564@$4
Cost of capital can still kill you here:
Payback@0% interest: 8.5 years @$3/gal, 6.4 years at $4/gal.
Payback@5% interest: 11.2 years, 7.75 years
Payback@10% interest: 19.2, 10.25 years.

Please note that I've heard that a battery replacement may be required after the five year point, at a cost in the thousands of dollars. My solution right now is to hang onto my current car until it wears out in the hopes that hybrid maintenance requirements will become better known, prices will drop and efficiency increase even more.

*Found by averaging city and highway EPA figures

But TOU is an advantage if you generate enough

[aegl]

Here in the S.F. Bay area the summer-time weather is more human-friendly, so air-conditioning needs are lower, and thus daytime summertime power consumption is lower.

I'm generating a small excess of power in the peak charging time (1pm-7pm on the E-6 tariff). Each extra kWh I make in that period gets me a $0.20865 credit with which to buy power at night (at $0.09418). On the standard E-1 tariff my excess daytime power would only reap $0.1143, the same as my cost for buying night time power.

Forcing people onto TOU tariffs will make it hard for small systems to break even, but shouldn't have as much effect on larger systems.

The long term trend is toward TOU systems for everyone (at least if the PUC grants the wishes of the utility companies). So another way to look at the current situation is that people who use large amounts of power during the peak hours are currently getting a free (well cheap) ride from the utility companies, and those days are numbered.

Re:The math will never come out with current panel

[Hoi Polloi]

"Plenty of empty land near the coasts around the world to use for this."

Ummm, have you ever been to the US?

Yep, playing politics even on Slashdot

[marcus]

Big headline:

      CA Solar Use Falling Because of Economics

The statement is false.

Solar use is NOT falling in California, only the rate of rebate applications is.

Re:Yep, playing politics even on Slashdot

[dgatwood]

Actually, no, the Slashdot story is misleading. The law changed so that anyone using solar to supplement their power must switch to time-of-day metering. It isn't a requirement for the rebate. It is a requirement for all installations. As such, solar panels no longer pay for themselves in a reasonable period of time, and for many homeowners, their power bills increase after adding solar systems.

All indications are that solar installations have dropped significantly. If you're smart, now is the time to buy the solar systems while demand is low and companies are scrambling for every sale they can get. The law will eventually be fixed, and even if it isn't, you can always buy enough panels to completely remove your grid usage except when it is cloudy for several days in a row, and under those circumstances, the solar system will pay for itself and them some.

Re:Yep, playing politics even on Slashdot

[Damvan]

This does not apply to existing installations. Only installations that applied for the rebate after January 1, 2007. My system was installed 3 years ago, and I have not been forced to change to time-of-day metering.

Re:Yep, playing politics even on Slashdot

[dgatwood]

I'm not at all surprised that the law applies exclusively to new installations. What I meant was that I didn't see any indication that it was the rebate that forced the metering, but rather the law about the installation itself. That would mean that it would affect new installation rates, not just rebate rates. Of course, without a cross-reference to the law in question, I'm just giving my interpretation of an article that gives its interpretation of the law, which makes my interpretation pretty far removed from a grounding in reality, so I could easily be wrong.

Re:The math will never come out with current panel

[SvnLyrBrto]

> Break even point, assuming 0% interest? ~10 years. I usually assume a car's lifespan
> at 10 years. Many last longer, but many die earlier.

Remember though, those numbers change when you separate out the Japanese cars designed and legitimately built in Japan from the fords, chevys, and chryslers; designed and built by those monkeys in detroit. Most of the hybrids that are on the market now are Hondas and Toyotas. So their lasting well past ten years can safely be assumed to be the rule, not the exception.

Granted, a lot of people don't *KEEP* their cars for their entire lifespan. But some of us do. I've had my Subaru for almost eight years now, and, excepting the possibility of accidents or moving overseas, I expect to put at least another 200K miles on it before I need to even think about replacing it. When I do so, the plan is to get a hybrid (Or, by then the NEXT next-big-thing might be available.), which I will ALSO keep for the lifespan of the (yes, it WILL be Japanese) car.

cya,
john

How could I NOT use solar power?

[quixote9]

Uh, not to be a jerk about this or anything, but without solar power I'd be dead in a few days. Of course I use solar power. That choice gets the comment one of my English teachers wrote over all my stuff: "Awk. Rephrase."

As with the English teacher, I have no idea how to put it better.

To answer the actual question, I'm with the crowd: yes, I'd really want to use solar power in the sense that the poll means it.

cheaper batteries

[zogger]

FWIW, if you have some leet home engineering skills for moving heavy objects, check out industrial electric forklift battery packs instead of going for the option of "solar" batteries. You'll get a lot more stored juice for the buck that way. Wherever you buy them from most likely can load the thing into your truck, at home, different story. I'd suggest renting a truck with a *stout* lift gate on the back (check load ratings on the liftgate, if not sufficient, you'll just have to deal with a normal truck bed), then perhaps renting an engine hoist and some good piano dollies, etc. Build your vented battery box first, after you have the correct dimensions of course, and maybe leave the front plate off, install the heavy steel battery pack, then screw and glue the front panel on (might be one option unless you opt for the forklift or heavy engine hoist). Maybe, cobjob to your level of expertise. They are heavy mambos, and you can get them at 12 to 48 VDC. If you've never seen one, wait until you see the busbars on them, the series connectors, solid bars welded to the terminals. They are *serious* battery packs, built for rugged use. They are deep single cells inside a steel box, with an open top, with lift holes on the side for attaching the lifting chains. Or even just rent a small forklift for that moving-in day. A lot of folks on a budget have used them in solar installs, work great. And *always* use distilled water to top them off.

$3.15/Watt thin film solar

[mdsolar]

At the top of this http://www.ecobusinesslinks.com/solar_panels.htm price comparison list I found Aten Solar selling at $3.15/Watt for thin film solar (minimum 32 panel purchase). They provide a 20 year better than 80% warranty similar to standard silicon panels. This won't fit on your roof and cover you power usage, but if you have yard space, this might get you going. This is amourphous silicon technology. -- Get Solar Power on your roof without the hassles: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Another problem: Contractor requirement.

[Ungrounded Lightning]

Another problem with most rebate programs is the requirement that it be installed by a licensed contractor - without the exception (available for construction but NOT for the rebates) that allows a homeowner to do the installation himself (with appropriate permits and inspections).

The price difference can easily eat more than the entire "rebate".

Re:The math will never come out with current panel

[Firethorn]

Remember though, those numbers change when you separate out the Japanese cars designed and legitimately built in Japan from the fords, chevys, and chryslers; designed and built by those monkeys in detroit. Most of the hybrids that are on the market now are Hondas and Toyotas. So their lasting well past ten years can safely be assumed to be the rule, not the exception.

I was comparing hondas to hondas in this instance. I wouldn't trust much of the detroit stuff to make it even 10 years. Still, I use the 10 year meterstick because it's easy, and the odds are against most cars making it past 10 years, even if only through accidents.

I will ALSO keep for the lifespan of the (yes, it WILL be Japanese) car.

I'd suggest against ruling out all non-japanese cars. I'd make the Japanese earn my business against all the other competitors personally. Eliminating choices out of hand isn't good for competition.

Independance, not economics

[Orig_Club_Soda]

When I attempted to get on the recall ballot as a candidate for governor, I advocated that all new structures in California have at least 1 solar panel, commercial buildings a number related to the surface area of the house.
If every building used solar energy then the general demand would go down. Additionally, in blackouts and outages, every building would have enough energy for lights and not motorized electronics.

Studying the economics on the individual level is a waste of time. Individuals use different amounts of energy. However, as a society solar panels will reduce energy from fossil fuels, reduce smog, and in the long run cost that the individual pays indirectly (such as the cost of a product that is relient on energy costs).

ad hominem, anyone?

[SuperBanana]

Sure, I find many informative pages on the subject - all from people with a vested interest in convincing you that solar power is a good idea, (either because of their politics or because they want to sell the systems to you).

How about challenging the math, instead of the people? Ie, using legitimate debate tactics, instead of engaging in ad hominem?

The output of the panels can be tested and verified, as can solar radiation for a particular area. The cost of electricity, interest rates, etc are all known facts...

Re:ad hominem, anyone?

[DerekLyons]

Sure, I find many informative pages on the subject - all from people with a vested interest in convincing you that solar power is a good idea, (either because of their politics or because they want to sell the systems to you).

How about challenging the math, instead of the people? Ie, using legitimate debate tactics, instead of engaging in ad hominem?

Pointing out a potential flaw or bias in a source of data is, in and of itself, a legitimate debate tactic. (And you might look up the meaning of ad hominem - it doesn't mean what you seem to think it means.)

Re:ad hominem, anyone?

[Abcd1234]

And yet you still can't disprove the math. Interesting...

MORE FEDERAL TAX BREAKS!

[Anonymous Coward]

All solar panel purchases, wiring, and home - off-grid conversion costs should be fully federally tax deductible.

Mr. Bush - Put your Money where your Mouth is - help End America's Addiction to Foreign Oil.

Strengthen national security though solar power!

HOA are a barrer for new or used

[ProfBooty]

i would be totally up for getting a set of panels, new or used, if they weren't prohibited by my homeowners assocation.

to be honest unless there is legislation otherwise, like for satellite dishes, HOA's are going to be as big a barrier as cost for a long time.

Re:HOA are a barrer for new or used

[Damvan]

California has the "Solar Rights Act" passed in 1979 to prevent HOA's from stopping solar installations.

Limits on Covenants, Conditions, and Restrictions to Restrict Solar Installations - The
Act prohibits covenants, conditions, and restrictions (CC&Rs), like those enforced by
HOAs, which would unreasonably restrict use or installation of solar energy systems.
(California Civil Code Sections 714 and 714.1)

Well...

[SvnLyrBrto]

> I'd suggest against ruling out all non-japanese cars. I'd make the Japanese
> earn my business against all the other competitors personally. Eliminating
> choices out of hand isn't good for competition.

The first two cars I owned, before the Subaru, were a chrysler and then a ford. I plan never to make either mistake again in my life.

Granted, that leaves GM. But their reputation for quality and reliability is right down there with the other two. (I did a *LOT* of research, both online and via print resources such as Consumer Reports, when I was planning my last purchase, before deciding on my Subaru.) And the performance of the company, in general, does not exactly inspire confidence of late. Maybe if GM is still selling re-badged Toyota's as Geos, I might consider one in the future. But I don't think that's the case anymore.

So that just about does it for american cars. That leaves Japan and Europe. And quite frankly, I don't need to pay an extra 5-10K for the "prestige of driving a european automobile". So that leaves the Japanese.

cya,
john

Might not need to go off grid

[mdsolar]

You might be able to zero out your bill with them while still forcing them to supply power. The problem in the article is about smaller systems. At a larger size, you are delivering power at peak and taking delivery at off peak which means you can have the deliver net power that you don't pay them for.
--
Get the optimal system size for TOU and keep it that way: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Link?

[Anonymous Coward]

I'm not saying you're wrong in this case, but most mercury present in the environment is either a localized contamination (coal ash dumps, for example) or overwhelmingly attributable to natural sources.

Do you have any authoratative links ascribing mercury contamination in the NE to powerplants as you claim?

Original headline

[mdsolar]

The original headline on the submission was "Time of Use Rates and Solar Power." I thought it would be an intersting discussion of how these rates affect decisions about solar power. You can clearly save money if your system is large enough to produce excess during peak because you get paid more for what you produce than you pay for what you take from the utility. The problem seems to be forcing time of use rates on people who get systems that only produce part of what they use during peak. The bigger problem I see is switching policies every year so that long term investments like solar power become unatractive in that way as well.
--
Try this math: compare our flat rate with your TOU rate (click the map): http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Re: Canada plant

[Anonymous Coward]

Wow...that's $7.50 per Watt of capacity. From what I've read, it sounded like $4-5/Watt was the breakeven point for capital investment in solar in California, not Canada. Actually, if I recall right, one of the original links off Slashdot cited a cost of $0.40-$0.50/kW-hr for this plant.

BTW, the 40% load factor is unrealistic...unless certain factors are partially aleady figured into the capacity. It's dark an average of 50% of the time year round and rated capacity is only achieved a couple hours a day under ideal conditions, we're talking above 50 degrees latitude, and that doesn't include weather.

Re:The math will never come out with current panel

[polderboy]

Apparently arivanov is referring to the "Centrale Solaire Thémis" near Targasonne near the Llívia enclave at the Spanish border in the central Pyrenées, app. 190 miles ( 300 km.) WSW of Marseille.... OK, I suppose you're American, so don't bother.

The plant you are referring to is west of Sevilla in Andalucía in Southern Spain, is situated on the Plataforma Solar de Sanlúcar la Mayor, it is a solar thermal (concentrating solar power, CSP) plant, sized 11,02 MW, and a SECOND one, 20 MW will be built on the same premises (as well as a range of different thermal solar power stations up to a total of 302 MW, in different locations). The Sevilla plant has been subsidized by the European Committee (5 million Euro's). Like ALL energy technologies are subsidized, either with state incentives for building power plants, or by putting incentives on the output (kWh fixed feed-in tariffs, the best way to make sustainable energy fly, like in Germany, which appears to be lying on another planet with its booming solar and wind energy businesses). OR by NOT including the huge environmental (and social) damages in the energy prices, such is being put into practice for decades for most of the fossil or nuclear options. I'm not considering the illegal, state-supported funding of nuclear power plants, such as Olkiluoto in Finland, off-course.

Electricity "at nearly normal costs" is relative. What is "normal"??? Electricity is being squandered massively, not only in the States, also in Europe. In my country, the Netherlands, consumer price is still an extremely "bearable" 21 eurocents/kWh. Solar electricity from photovoltaic sources by the best producers (e.g., vertically integrated concerns having the whole chain from silicium to solar parc building in one hand) is already being realized for 25 $ct/kWh, and your own Michael Rogol already has predicted, based on years of research and inside info from the top-notches in the solar industry, that in 2010 (that's in three years time, ladies and gentleman...), solar electricity can be PRODUCED (not sold!) for a very attractive 10 eurocents/kWh in Spain, 15 eurocents/kWh in Bavaria (south of Germany, where solar is booming like nowhere else), and 11 eurocents/kWh in south California...

http://www.photon-consulting.com/studie_the_true_c ost_2007_executive_summary.htm (english) http://www.photon.de/presse/mitteilungen/Hintergru nd_TrueCost.pdf (german, more extensive, with graphs)

It's not only a question of maths. It's moreover a question of political will, like Hermann Scheer, German politician and one of the central figures in the sustainable energy revolution in my neigbouring country, has repeatedly said. With political will in the highest gear, so many nice things can happen. 2,3 Gigawatts are already in place in Germany, only solar-PV, more than 300.000 systems, most of them in private hands and on civilian roofs. 45.000 jobs in solar energy alone (200.000 in the whole sustainable energy sector). It IS possible, in Germany it is REALITY.

They may have lost already

[mdsolar]

The rates quoted in the article go down to $0.163/kWh off peak but solar power as a rental deal is already being offered at $0.14/kWh flat rate for Southern California Edison customers. So by twiddling the rates, they've begun to price themselves out of the market. In fact, with a ~60% system you can likely zero out your Edison bill and just pay $0.14/kWh for that 60% under the TOU rates. So, you'll be saving 50% or so on your electric bill (compared to TOU rates). Check the offered solar rates for Edison and the other California utilites by clicking the map at the bottom of the page at any of the links here: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Re:They may have lost already

[Locutus]

that's right, I remember someone was offering to install the PV system on residential homes and essentially rent the power to the homeowner at a fixed cost. I wonder if 'fixes' to the rebate system didn't eliminate that situation from the program. No doubt there is some discussion inside the energy companies on how to stop this.

Given what you said though, I wonder why there wasn't a massive move over to that configuration instead of the 78% drop off for new systems because of the newly added TOU clause?

LoB

Re:They may have lost already

[mdsolar]

You don't get the rebate if you rent though I think you can get it later if you decide to buy later. You just get a lower price (in this case) for electricity. The company tries to match the utility rate for each utility with net metering, but sometimes they come in a little high or a little low. The formula is to divide what the utility says it collected for residential by what it says it delivered. With staged rates and time of use rates, things can get a little confusing but for time of use one can usually save some money.
--
Rent solar power: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Re:They may have lost already

[Locutus]

I figured the company installing the panels on your behalf would get getting the rebates since it's a tougher business model without the rebates. For instance, a smallish 2.5KWh system runs around $20K and in our area would average about 5 solarhours per day or 2.5K*5=12,500KWh @ $.15/KWh is $685/year times 20 years would be only $13,867. They'd have to charge around $.25/KWh to just about break even and that's not including the cost of the money.

I think they currently need the rebates to make it work.

LoB

Re:They may have lost already

[mdsolar]

Here in Maryland the rebates are not so large, but neither are they available to the company. I don't know about California. But, the picture is not so grim as you think. There is accelerated depreciation, federal tax credits and renewable energy credits together with scale and verticle integration. The scale gets you to about $1.50/watt at the factory so the trick is to keep the further assembly and installation costs low by being able to schedule efficiently, basically the same way that UPS does. Currently, in the residential market, the panel producers, hardware producers, inverter producers, wholesalers and installers are all seperate businesses. Your retail price goes up everytime there is idling or a mismatch in equipment. One installer here lost half a day not long ago when the supplier sent the wrong parts. You can't leave the panels on the roof if they are not secured, so down they all came again with much cursing and moaning. You are paying for that. So, taking a good chunk off of your $20K figure is a big part of the business model.
--
Need more panels? Add them in at no charge. Need fewer? Same deal. Anticipate the utlities: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Solar Rights

[mdsolar]

California's Access law is one of the better ones. They also exist in
Arizona (tested in court)
Colorado
Florida
Hawaii
Indiana (planning zoning=HOA?)
Maryland (after 1980)
Massachusetts (specifically including in the yard)
Nevada
and North Carolina (Chapel Hill only)
As can be checked here: http://www.dsireusa.org/summarytables/index.cfm?&C urrentPageID=7&EE=1&RE=1. They basically help with HOAs for the most part.

http://mdsolar.blogspot.com/2007/01/slashdot-use rs-selling-solar.html Senator Menendez (NJ) has introduced a bill in the Senate which has also be introduced in the House too (Cardoza CA and Ferguson NJ) that would do the same kind of thing http://www.solarbuzz.com/News/NewsNAGO325.htm nation wide.
--
Save with Solar: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Our new system

[brjndr]

My family recently put in a solar system while constructing our new home, and it's been up and running for about 4 months now. We live on an orchard in California's Central Valley (near Tracy), and we get plenty of sun. The system powers the home and also meets any electrical needs maintaining the orchard may have. Our power is provided by PG&E.

Prior to putting in the system, we estimated our electrical need, and tried to put in a system that would result in not having to pay anything all year. The system ran about $150,000, and the rebate was around $45,000. It's a large array, but we have space so it's kept in a fenced area next to the house, not on the roof. In our previous home electrical bills ran in the $400-$1000 range depending on time of year. Temperatures easily hit 100 degrees for weeks at a time in the summer, last summer we had a few weeks of over 110 degrees. Our electrical need is also high, since we have to get our water from our well using an electric pump, run our air conditioning constantly in the summer (my grandmother lives with us, and is home all day), and we bought some electric appliances.

Since installing the system, we are averaging a credit of $550 a month, which we can carry for up to 12 months. We haven't used the air conditioning, but now the temps are hitting 90, so we'll see how the increase in sun and the increased use of air conditioning balance out. I expect our credit to increase.

For us, the system made perfect sense. The ROI was originally estimated to be about 7 years, and the panels are warranties far beyond that. We purchased electric appliances because we could use them without worrying about driving the bill up. The exception is we have a gas cooktop, which we preferred for cooking. Not everyone has the space to install the amount of panels we did, but neighbors have been stopping by and asking questions, and a few figured out it would be a good investment for them as well. The panels take up about as much space as 3 or 4 of our trees would have, but those trees (almonds) couldn't produce anywhere near the return.

The initial investment was high, but it made financial sense for us, and we had the space to put up a large enough array to meet all our needs. The rebate from PG&E really helped us in our decision, but they benefit every month with the surplus electricity we produce which goes back into the grid. We're considering getting electric utility vehicles for the orchard maintenance, which may also take a larger initial investment, but should be cheaper to run since we can just plug them in instead of filling them with diesel. We're still doing research into how their performance is.

I've had solar power in CA for three years

[BCNeuman]

I installed solar panels on my house in California three years. My system is grid connected (through Southern California Edison), and my "net metering agreement" did not require that I switch to time of use metering. My system is 3.5Kw, and I generate about 5.5 MWh per year. My power bill runs at about $20 per year (this is the cost of the "basic" charge for connection to the grid. There is more information on my system at http://solar.hmtech.info./

The net metering agreements are set up (if you do so as a consumer instead of as a real producer) so that your power use is netted over the course of the year. If you generate more dollars (it is the dollars that are netted, not the KWh) than you consume, the utility keeps the difference. If you generate less, then you pay the difference. My net use in KWh ends up around zero.

I live on the west side of LA, where it doesn't get very hot. If I were to switch to time of use metering (which is my choice, not mandatory) I would generate more of a credit than I consume at night. Since SCE keeps the difference, that would really only make a difference to me if I consumed more power at night then I do (which I keep low through conservation).

The possible problem that others may be facing is that if they are in a hotter climate, and run air conditioning every day, then they have larger consumption during the day. I only had to run my air conditioner three days last year, and my air conditioner draws 6 KWh - i.e. if I did this everyday, I would be a net consumer of power during the day. Personally, I chose not to do time of use metering because the "basic" charge for a smarter meter is higher. Since excess generation does not credit against the basic charge (only the power charge), it would have made my yearly cost about $20 per year higher.

I do not know if new "net metering agreements" are requiring time of use metering, but Edison has been rolling out their new smart metering system ahead of schedule in some areas, and I think that they may be starting to impose such requirements independent of whether one has solar power. They have proposed a rate structure for time of use metering that that I think they intend to eventually convert all users to, as their smart metering is rolled out to more locations.

Responding to a comment about whether solar power increases the assessed value for property taxes in California: while many imrpovements will (though they don't trigger a new assessment, they just add to the assessed value), solar power installation is specifically exempted, so it will not increase the assessed value for tax purposes.

It's still a luxury

[ml10422]

We live in California, and had a photovoltaic system installed last year, with the time-of-use meter and the rebate and everything. None of that stuff is a deciding factor.

Solar electricity is simply too expensive for most homeowners. Having solar on your house is still a bit of a luxury item, and a status symbol (among the right crowd). Hopefully, the systems will become more affordable soon.

Re:Batteries-already done

[darkwing_bmf]

Interesting comment. One can analyze the economics of such a decision by comparing ones expected return on investment (savings) of the energy saving device with the expected return if that money were someplace else (stocks, bonds, etc...). One problem is that most of these devices don't have an infinite lifespan. Another problem is once the up front money is spent, it's gone. You can't use it for anything else, including future cheaper and better energy saving devices. For most people it is still cheaper (and more rational) to pay the electric company to deliver power to them than it is to make it themselves. This situation is likely to change over time as technology improves and non-renewable energy sources become more expensive.

TOU not that bad

[khallow]

Time of use (TOU) pricing isn't that bad. The problem here is that it's only going to be applied to a small group rather the general population. My preference is for most of the cost of the electricity to be passed directly to the customer much as what was done in San Diego region before and during the early part of the California electricity crisis.

ad hominem circumstantial

[SuperBanana]

Pointing out a potential flaw or bias in a source of data is, in and of itself, a legitimate debate tactic. (And you might look up the meaning of ad hominem - it doesn't mean what you seem to think it means.)

I did look it up. You used ad hominem circumstantial: you said all the people supplying the data showing profitability of solar panels had a "vested interest" and insinuated that their argument was predisposed. Wikipedia (and other sites) define ad hominem circumstantial: "Ad hominem circumstantial involves pointing out that someone is in circumstances such that he is disposed to take a particular position. Essentially, ad hominem circumstantial constitutes an attack on the bias of a person. The reason that this is fallacious is that pointing out that one's opponent is disposed to make a certain argument does not make the argument, from a logical point of view, any less credible; this overlaps with the genetic fallacy (an argument that a claim is incorrect due to its source).

You did this instead of actually providing evidence that the data is wrong, or even presenting alternative data. You simply said, "They're liars!".

Stop using logical fallacies and prove me wrong on the original topic- whether the data showing solar panels pay themselves back within a few months to a few years, usually well before the warranty expires.

Re:Batteries-already done

[Dun Malg]

Instead of speculating, how about using google to see the thousands and thousands of installations where they DO use battery banks for homes? It's doable. It just is. People spending half a million to a million bucks on a house in California can afford 40 grand for a very sophisticated rig, and tie it directly into their long term mortgage Think so, eh? Think we're all rich because the real estate where we live is more expensive? Most people attempting to buy a house in the expensive parts of california are mortgaged to within an inch of their lives (or more, as the foreclosures illustrate). That additional 40K is enough to push up the monthly loan payment on a half million bucks by more than you'd save in electricity. But it's easy to stand on a soapbox and tell other people what they can afford, right?

Illegal

[mdsolar]

You can have your own generator and plug some thing into it, but as soon as it is actually connected in with the grid, you have to have an interconnect agreement with the utility. There has to be anti-islanding switching to protect people who are working on the lines during an outage. You can't have a "seemless" system without telling the utility.
--
Solar power without the hassles: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

Scale

[mdsolar]

This is just right. Going to a 500 MW/year production facility brings costs down by as much as a factor of 4, but you need the market to be there to risk the large production capacity. The market is arriving now as we see interest in renewable energy for its own sake growing. The effect will be to make renewable energy cheaper than non-renewable energy. What is meant by cheaper? For wind, in the standard way, cheaper delivered as it now is in Texas. I just lost a customer to that which is fine by me. For solar, this means cheaper than delivered power since it is already in place. This thing with time of use rates actually does a big favor for the way we do business. We can rent a customer a system that zeros out their utility bill but does not actually cover all the power they use. It produces at peak so it does not need to owing to the price difference. We charge at about the average rate but for less electricity since the system does not need to be so big. Presto! A big savings for the customer.
--
We're also good if things change since we can adjust the system size again to optimize for a different rate structure.

Where does this leave the utility? In a pretty good place. They'll need to start thinking more about how they can server their customers. What can they do to cover the cost of providing a local two way connection which won't drive customers off the grid entirely? It is a conversation we need to have.
--
Time of use rates mean you save when you rent solar: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

That's up to us

[mdsolar]

With a very rapid conversion to renewable energy, the demand for non-renewable energy will be much lower. I'd like to see coal, gas and oil so cheap that it isn't worth pulling out of the ground. Most likely you are right, we won't anticipate reduced supply, but it would be smart if we did.

Compressed Air Storage

[mdsolar]

There is a wiki on this, a couple of facilities are already operating: http://en.wikipedia.org/wiki/Compressed_air_energy _storage.
--
Generate peak power: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html

if AC=air conditioning? Then AC is not required

[zahl2]

...in all of California. Remember that CA stretches for a good distance North/South. The temperature is also moderated by the proximity to the ocean.

But wait a few years and it'll get hotter.

You're both right, actually

[Travoltus]

I live the lifestyle he's talking about, and after reading you, I ran the numbers given my wife's sister's household income. Yup, that extra $40K woulda splattered us, given her loan rates (not mine).

Which is why I'm fairly reluctant to preach about this, at least until Aaaahnuld gets his act right.

So switch, then switch back

[lpq]

It may be 1 year, more or less, but after getting rebate and switching, can't you switch back to flat usage?

A TOU-rate, should benefit a properly outfitted solar customer -- they could sell 32cent kwh during day, and only pay 10cent kwh during evening. During the day is when you should get the most use off of a solar system.

I don't know that I believe it is a bad thing for PG&E to want to measure electricity -- if they don't measure, how do they find out whether or not the rebate program is cost effective? How can they do the research in "average", "real" homes? Does converting to solar help or does it encourage higher energy usage due to a drop in overall rates?

Since CA utils are strapped for electricity (years of NIMBY protests keeping plants from being built anywhere) and their most costly time to provide energy is during the day -- how can they "encourage" customers to use less (or generate more) electricity during the day when needed, vs. evening when the system is less stressed?

The PG&E rebate on solar is only part of the refund package, no? Isn't there a state refund as well, or are those the same thing?

I've thought about converting to TOU, but I don't know if it would benefit or hurt me. I don't have air conditioning, but I am home. Probably less use during day, but I don't know if it would be enough to save.

At least by requiring an initial change to TOU, PG&E can measure the average benefit provided by solar and use that in future planning, rebates, etc. Otherwise, how can they tell? Wouldn't they be "flying blind", otherwise?

My experience

[TEG2]

Contrary to the general gist of this article, I was disappointed that the high differential TOU rate wasn't available when I signed up last year. They had stopped letting people on the PG&E E7 rate, and gave (instead) the E6 rate with less difference between daytime and night time rates. For those with enough solar panels to nearly cover all their power use this resulted in less savings. Apparently at the beginning of 2007 they are letting some new solar customers get into E7 again, but those who were given E6 last year can't switch. I hope they sort this out so it is more of a "no-brainer" to go solar. As far as I know, CA prop13 law does have your property tax go up if you add improvements to your property, but there is apparently an exception being made for solar systems right now. Also, in my case, the TOU meter costs me about $12 per month which is basically a "grid access fee", so I still have to pay PG&E about $140/year even if I generate more power than I use. (If you generate more credit than you can use your bill becomes $0 as they will not pay you for excess power, only offset your usage fees with credits. Even if you get your use bill to $0 you still have to pay the meter charge) The new daylight savings time worked against me. The way PG&E E6 & E7 TOU work you don't get the higher rate in the mornings while generating power since they shift the "peak" price later in the day. So good solar power made in the 9am-1pm range tends to get you the lower $ credits, then you are in the "sweet spot" from about 2pm-5pm, then the solar panels stop producing but you are still on the peak rates until 6 or 7pm. So that "dinner hour" when everyone is home from work, the oven & A/C is running, but the sun is setting wipe out some of the credits gained earlier in the day. To add some insult to this, the recent changes to daylight savings were not reprogrammed into my TOU meter, so (for instance), during the month of April my peak rates started later in the day and stayed until 8pm rather than 7pm so even more credit was lost. It was probably easy for PG&E to decide not to reprogram for the extended daylight savings since it worked out in their favor. I heard in Germany the government offered very good rates for power sent back to the grid, and they allowed you to be paid for any excess not just to let you zero your bill. The rates are so good that banks would loan almost anyone money (if they had the space) to put in solar panels. So now they have farmland and previously empty fields filled with solar arrays and people actually make a living from "farming out" their land to solar. We could get off of burning fossil fuels for power if the US government were willing to offer incentives like that. Germany has been doing and they are more northern with less sunlight to benefit from.