Rooftop Solar Could Reach Price Parity In the US By 2016

Lucas123 writes: The cost of rooftop solar-powered electricity will be on par with prices of coal-powered energy and other conventional sources in all 50 U.S. states in just two years, a leap from today where PV energy has price parity in only 10 states, according to Deutsche Bank's leading solar industry analyst. The sharp decline in solar energy costs is the result of increased economies of scale leading to cheaper photovoltaic panels, new leasing models and declining installation costs, Deutsche Bank's Vishal Shah stated in a recent report. The cost of solar-generated electricity in the top 10 states for capacity ranges from 11-15 cents per kilowatt hour (c/kWh), compared to the retail electricity price of 11-37 c/kWh. Amit Ronen, a former Congressional staffer behind legislation that created an investment tax credit for solar installations, said one of the only impediments to decreasing solar electricity prices are fees proposed by utilities on customers who install solar and take advantage of net metering, or the ability to sell excess power back to utilities.

Comments

They WILL FIght Back

[Anonymous Coward]

In the craphole region in which I live they've already passed ordinances about things like wind turbines within city limits. They call it an "eye sore" and "disruptive." That's how the utility companies will outlaw solar paneling after donating generously to their politician buddies. Either that or they'll so overregulate them that the price will skyrocket beyond most people's financial reach.

Re:They WILL FIght Back

[Anonymous Coward]

Everybody knows wind turbines are eye sores.

They obscure all the lovely smoke stacks.

Re:They WILL FIght Back

[Harlequin80]

There was a wind turbine near me that was removed by local council order. It was one of those spiral tube looking ones and the person had put it up in their front yard on essentially a flag pole with guy wires.

The thing had a fair amount of slap in the pole which was kinda scary to watch. But the main thing was this thing screamed when its speed got up. Not sure what it was, whether it was the bearings, the motor or maybe the brakes but it started to sound like a jet turbine spinning up when it was going fast (and bloody hell did it spin fast!)

I used to drive past it on the way to and from work and could comfortably hear it over the car's engine and aircon with the windows closed.

Re:They WILL FIght Back

[Shakrai]

They call it an "eye sore" and "disruptive."

They're most definitely both of those things. I had the misfortune of living through the construction of the Mehoopany Wind Farm. Think 24/7 heavy truck traffic, seemingly random road closures to move turbines/blades that were never communicated to the locals (it's awesome being half an hour late for work because they changed their schedule with no notice), huge amounts of deforestation (nine thousand acres worth), formerly crystal clear streams filled with silt from runoff, and dozens of blinking red lights where we formerly had clear nighttime skies. Take a look at this to get a feel for the impact of but one small segment of this wind farm. Look at the footprint for a single turbine and multiply it more than one hundred times, all for this one wind farm.

9,000 acres of real estate for a lousy 141 megawatts of electrical production that's wholly at the mercy of mother nature. Let's contrast that to nuclear power, the cutting edge of 1950s technology: Nine Mile Point occupies 10% of that footprint (900 acres), hosts a second power station on the property and between the two can generate 2,599 megawatts 24/7/365 regardless of the weather. That's more than eighteen times the electrical production for 10% of the land. Zero carbon emissions for production; a non-zero amount overall (plant construction and fuel mining each have a carbon footprint) but that's true of wind as well.

Wind power is a joke regardless of how you look at it. It's more environmentally disruptive than yesterday's technology and doesn't scale nearly as well. I'm not anti-solar; solar can be placed on otherwise wasted space (i.e., my roof) and is an awesome solution for peak power demand (nuclear doesn't work well here, it's better suited for base load)

Re:They WILL FIght Back

[PopeRatzo]

They're most definitely both of those things.

Thank goodness coal-fired power plants are so aesthetically pleasing and pleasant to live around.

Re:They WILL FIght Back

[Shakrai]

Other than the short term inconvenience of a major infrastructure project going in (oh no!) your long term view of the even longer term benefits of the site seem awfully jaded given the extremely low impact (i.e. none) to your daily life.

It lasted six years dude. The effects were even more obnoxious than I listed; I remember dusting the house every bloody day because they were stirring up that much dust and dirt. They destroyed our local roads and paid nothing towards the repair of them. I moved out of that area a full year after they completed construction and the streams still weren't clear. That's what happens when you clear cut thousands of acres of forest. The out-of-towners they trucked in for the job showed no respect to the local community. The complaints ranged from the trivial (speeding, ignoring stop signs) to the obnoxious (unnecessary jake braking at 3am, sexual innuendo on their CB radios) to the criminal (assault and rapes tripled in Wyoming County during this project).

Relations with the locals deteriorated to the point that people were literally pulling guns over road closures and other matters that seem trivial when viewed in a vacuum but which were somewhat understandable if you lived through it. I moved to the area in the middle of the project and tried to play devil's advocate in favor of it; I'm usually pro-development and at the time believed in wind power. After six months of living through this hell I had grown frustrated enough to join the locals in waging an undeclared war against BP and their subcontractors. My preferred method of acting out was to fuck with the 18 wheelers that tailgated me. "Hmm, 60 in the 45 isn't fast enough for you?" [sets cruise control for 30] "Oh, you're going to pass me?" [floors it] "Yeah, how'd that work out for you? Get back there bitch. That's right." [back to 30, rinse and repeat for 15 miles]

The sad thing is I'm really not the NIMBY type; I would have been willing to tolerate the obnoxiousness if there was a net gain to society, but on balance there wasn't. 141 megawatts and for that we destroyed 9,000 acres of formerly pristine wilderness. They could have built a nuclear power plant that would have consumed a fraction of that land while producing many times the power. In reality you wouldn't have to destroy wilderness to build new nuclear plants; there are plenty of abandoned industrial sites across CONUS that would accommodate them.

Incidentally, it fails from an economics standpoint just as badly (if not more so) as it fails from an environmental one. That wind farm produced the staggering total of ten permanent jobs. A conventional power plant employs hundreds of people and doesn't require thousands of acres of wilderness. Heck, even the small businesses around here that install solar panels usually employ more than ten people.

I'll repeat: Wind power is a joke.

Re: They WILL FIght Back

[Shakrai]

Call me whatever you'd like, I'm not going to lose any sleep over it.

Things got so bad that they couldn't even convict the people that pulled guns on BP employees; they essentially got jury nullification because the DA couldn't find 12 people in the entire county that didn't know someone who had been trodden upon by BP or a subcontractor thereof. My actions paled in comparison to what some people did, and yes, they were passive aggressive. I won't apologize for them either. You live through it and see how long your patience lasts.

If it makes the green people here feel any better that same area is the middle of the Marcellus shale natural gas boom. The gasholes are every bit as obnoxious as the wind people. They do employ more locals than the wind farm, so they're somewhat better tolerated but at the end of the day they're every bit as disruptive to the local life and ecology.

Re:They WILL FIght Back

[Rei]

Actually, the statistics are precisely opposite. The lower the turbine and the higher the RPM, the more birds it kills, while the higher the turbine and the lower the RPM (aka, the wider the blade radius), the fewer birds it kills. Also, tower design plays a major role. Those truss-style towers popular with small-scale turbines are the worst, as birds see them as potential perches / roosts.

The worst wind farm in the US for bird deaths by far is Altamont Pass, especially their older turbines, which look like this. They're pretty much a bird cuisinart, they kill thousands of raptors every year and have had a significant impact on California's bird of prey population, while most wind farms have an irrelevant impact on bird populations.

Re:They WILL FIght Back

[Rei]

It depends on how you measure it. For example, here it says that solar is rapidly nearing cost parity except in places where restrictions and fees on net metering are in replace. But it's only fair that there should be such fees.

Part of the reason for this battle in the US is the stupid way US consumers are billed, you usually pay a single per-kWh fee. Here in Iceland our electricity bills are broken down into a "distribution fee", for the infrastructure, and a "generation fee", for the power. Surprise surprise, all of that infrastructure costs some serious money, about as much as the cost of generation itself. If a person uses solar and net-meters out at zero, they're still using all of that infrastructure (unless they're off-grid, but nobody's arguing that off-grid is anywhere near price parity). Even more than that you're relying on the existence and functionality of power plants to keep the lights on during the day. If everyone did like you, then there'd have to be instead of power plants massive daytime-energy-storage buffers, be they batteries, pumped hydro, etc (in addition to all of the wires, transformers, etc).

Now if you don't have to pay the utility, who exactly is supposed to fund this stuff? It's not cheap.

Yes, many US states require free net metering and power resale. It's the law, so utilities have to do it. But all you're doing at the time being is transferring the solar-generators' share of the infrastructure costs onto the non-solar-generators share. So when you report that these people can "break even", is that really a fair comparison?

Don't get me wrong, I'm a big solar fan. And I think that to reach true parity subsidies - such as these free net metering laws - are a great way to help get solar to that point. But let's not kid ourselves, it is a subsidy.

(Things would be a lot less controversial if you'd properly break up your power bills into distribution vs. generation costs. Personally I think bills should be even further broken down to time intervals over the course of the day and have the purchase / sale price of electricity match the actual market price for that time. It'd be a big boon for solar users, at least in warm places with low to moderate market penetration where midday electricity is expensive and nighttime electricity is cheap)

Re:They WILL FIght Back

[Rei]

Everything you wrote is irrelevant. If they're running your meter forward when you buy and backward when you sell, then you're getting the same price for purchase and sale. If you use X kilowatts and sell X kilowatts, in most places with net metering, your bill is free, or nearly so. THis should not be, because you're still moving a lot of power back and forth over a lot of expensive hardware, and relying on very expensive infrastructure to ensure that you stay powered at night. All of this hardware costs about as much in terms of amortized capital costs and ongoing maintenance costs as the actual generation of electricity at a power plant. You should be responsible for bearing your share of this cost.

People should agree to accept responsibility for their share of the infrastructure costs, infrastructure that they're clearly using just as much if not more than other customers, and instead argue on other issues that could benefit them, such as time-of-use valuation of electricity.

if something happens to the connection on my line I typically have to pay for it

I am, of course, obviously not talking about the couple dozen meters of wire from your house to the grid. I'm talking about the grid itself. If you want to disconnect your home's grid connection from the grid, by all means, you should then be under no obligation to pay for grid construction and maintenance. But as long as you want to use it, you should be paying for it.

My two cents...

[Anonymous Coward]

I think it'd be fine for utilities to charge something nominal for the privilege of solar. After all, you're not off the grid AND the power company has to deal with the upkeep of the cables. Provided it's not a money grab... that it's justified.

Net metering is when it runs backwards? That's probably find in a single month. But to carry it out over the year doesn't seem fair because during winter months, the solar panel user really is taking advantage of the grid.

As for the pricing when there's a surplus during the summer (when you sell it back), as I said before, you're not dealing with the cables/power lines... they are (the power company).

If solar power reduces carbon output from coal, good. Personally, if I could afford solar panels, I'd be interested in what uses it could provide during power outages combined with a battery backup for certain breakers/circuits (fridge, lights, and maybe one for TV watching).

Re:My two cents...

[bored_engineer]

I think it'd be fine for utilities to charge something nominal for the privilege of solar.

I couldn't agree more. Where I live, I pay a monthly fee simply to be connected to the grid, whether I use any electricity or not. I assume that if micro-generation becomes common that the co-op must increase this fee. I will happily pay an increased fee to have the night-time and winter generation that are impossible with solar.

Personally, if I could afford solar panels, I'd be interested in what uses it could provide during power outages combined with a battery backup for certain breakers/circuits (fridge, lights, and maybe one for TV watching).

A transfer switch, combined with a good inverter (or a pair, depending on your load) can provide this today. (The transfer switch is mandatory for any solar install, anyway, so as to keep utility workers safe.) In fact, this has been possible for at least 15 years. In fact, a good inverter can act as the charge controller for your batteries, as well as manage a back-up generator to keep the batteries charged during an extended outage. If you want a good system that provides backup power, I would talk to somebody about designing it for you, rather than trying to cobble it together yourself.

Re:My two cents...

[dgatwood]

Net metering is when it runs backwards? That's probably find in a single month. But to carry it out over the year doesn't seem fair because during winter months, the solar panel user really is taking advantage of the grid.

How is that not fair? As a solar panel user, you’re no different from any other generator company. If I’m producing power, I darn well expect the power company to pay me for it, just as I expect to pay them if I’m using more power than I produce. What would be unfair would be an arbitrary limit to how far ahead you can build up bill credits towards future bills, because that would mean that I produced power that the power company benefitted from, and sold to somebody else for more than they should have paid me for it, but then didn’t pay me for it. That’s called stealing where I come from.

Besides, on average, solar power users produce power during the day, when demand is high and the cost of production is relatively high (because peaker plants are expensive). They consume power mostly at night, when demand is low and the cost of production is low. So no matter how long a cycle you average it over, the power plants are making a big profit from buying relatively cheap solar power instead of expensive natural gas peaker plant power (while selling that power at the same price). That more than pays for the negligible marginal grid maintenance costs arising out of providing power to one extra home.

And if you produce more power than you consume for a whole year, the power company gets an even bigger windfall profit. In most places, net metering happens on a one-year cycle. They pay you if you use less power than you produce over the course of that one-year period, but at least here in California, they pay a whopping 3 to 4 cents per kWh (less than half the production cost for solar, last I checked). As a result, there’s really zero advantage to overbuilding; the goal is to get as close as possible to breaking even over the year, without going significantly over. And, of course, they resold your extra power at up to 38 cents per kWh....

don't tax alternative energy and transportation

[presidenteloco]

"fees proposed by utilities on customers who install solar and take advantage of net metering, or the ability to sell excess power back to utilities"

this reminds me of the states that are passing taxes on electric vehicles because they don't pay gas tax.

There is a monumental, staggering level of myopia in those who propose and enact measures like these.

We have to transition to ~ 90% of the transport and energy in the economy to non-fossil, in a damn hurry (e.g. 2050), and we are way less than 1% of the way to where we need to get, so why the H3LLLLLL! would anyone be trying to put the brakes on the change already. Insanity, or stupidity of the highest order.

Re:don't tax alternative energy and transportation

[Charliemopps]

The price of electricity is not just the price of generation.
The price of transportation is not just the price of fuel.

If you gave fossil fuels the same advantage of not charging infrastructure costs, taxes, government regulations on production etc... like you do with solar, you'd find that they are virtually free. There is no conceivable way solar is even remotely comparable until the government steps in and starts manipulating the numbers for the public good. You can argue that the CO2 issue is important enough to justify that interference, but lets not lie to ourselves about the numbers.

Re:don't tax alternative energy and transportation

[dgatwood]

But we need to pay for infrastructure. SO we need to tax electricity to recoup lost revenue form the gas tax.

It would make more sense to crank up the diesel tax. Big trucks cause about three orders of magnitude more damage to roads than cars do anyway (one 18 wheeler does as much damage as 9,600 cars, according to the GAO), so it is only fair that trucking companies should pay essentially the entire cost of upkeep. If they raise the taxes high enough, perhaps we’ll see a resurgence in the use of trains for shipping (which is more energy efficient, too).

Re:don't tax alternative energy and transportation

[rahvin112]

You are so very wrong.

Solar IS cost competitive. And with in a very short period, if current manufacturing price drops continue, it will be the cheapest source of power. But sure, ignore the real numbers the real reality of the situation if you wish. These numbers have been the talk of wall street for more than 2 years. Solar companies are turning down investment right now because there is too much being offered. But feel free to continue to display your ignorance. Even a fool could verify the real numbers with Google.

"eye sore"

[grimJester]

You know they're desperate when the only argument against new technologies they can come up with is that they're ugly.

Re:"eye sore"

[davydagger]

Don't forget these imaginary "sicknesses" due to wind turbines. All the while forgetting the real health hazards of fracking. Thats the thing about "conspiracy" theorists. Is that they have the demor, and attitude of a truth seeking movement, ignoring the low hanging fruit of very obvious ills in society, to at best reach around conjectures and "what-ifs", that convienantly blame who they want to blame for society's problems.

Re: "eye sore"

[Anonymous Coward]

It's absolutely true. Most people don't know this, but a herd of elephants produce a constant low frequency.

At first it was theorized that the low frequency sounds were communication to keep the group connected even over long distances, but it is now accepted by leading researchers that the low frequency hum is actually a defense mechanism by the elephants to cause cancer in predators, or in some cases a particular asshole elephant in the herd that gets on their nerves.

We may think that we discovered that low frequencies of sound cause cancer by studying people that obviously hate windmills, but nature actually invented it first!

Isn't nature amazing?

Re:"eye sore"

[westlake]

You know they're desperate when the only argument against new technologies they can come up with is that they're ugly.

A lot of money is being spent here to reclaim waterfront property for green space, nature reserves, parks and recreation. Ugly comes at a price that not everyone is willing to pay anymore, and the geek needs to see that clearly.

Re:"eye sore"

[fustakrakich]

Don't know about cancer, but some of those frequencies can give you a good case of the runs. Happened to me once at a Joe Walsh concert...

Re:"eye sore"

[Ol Olsoc]

What is confusing is, why is there a debate about wind turbines on an article about SOLAR?

False equivocation? The bizzare ability of some folks to add up equate supposed disadvantages of multiple different technologies and lump them into one pile of fail, while some existing technology is heralded as perfection, ignoring any problems it might have?

Wind turbine are probably irritating and it might be better to install them in deserts, away from residences.

Kind of a whooshing sound, if they are a nuisance to anyone, that same person would not be able to live in a suburban environment, with buses and traffic and lawnmowers and leaf blowers and all.. And jet traffic would be completely intolerable for them. I've stood within 50 feet directly under one, and there simoply isn't all that much noise. On the mountaintops where they are installed here, the wind through the trees makes more noise.

Regardless, the big advantadge of the solar panels and their proliferation is that the people installing them don't give a flying fig about the naysayers. They've heard so much bullshit about how the panels will self destruct long before the investment return or warrantee period, how solar will never ever be able to provide their needs, and how the terrible poisons involved in making solar panels are somehow worse than the benzene in the gasoline they inhale every time they pump it or the MTBE octane booster isn't bad at all, the lead that used to be in it wasn't a problem at all, and that nothing beats good old fossil fuel, which we'll apparently have forever and ever, world without end, amen.

The solar users just install them, use them, and don't pay much in utility bills - or attention to the naysayers.

Re: "eye sore"

[Zontar The Mindless]

Aboard an incoming flight, you can see Beijing's air long before you can see anything of the city itself. Looks like a big inverted bowlful of smoke about 5 km high and 50 km in radius.

Re:Subsidies

[rmdingler]

There is no side of the energy industry that doesn't get subsidies, least of all the presently successful variety.

Tax credits end in 2016

[grimJester]

There's a 30% tax credit expiring in 2016. Not sure what you mean about an "idea" and being "scalable"; it's just a bank projecting in what areas photovoltaics will be worthwhile when. After 2016, you'll presumably still have new installations worthwhile in the south of the country and the area creeping northwards as prices continue going down.

With or without subsidies?

[Karmashock]

Prices are so distorted at this point it is almost impossible to tell what anything costs.

Re:With or without subsidies?

[tomhath]

His prediction that there will be a big increase in solar installations is based on what will be happening to subsidies in the next few years (he expects a rush to install as much as possible before the programs expire). In other words, the actual cost of solar won't really reach price parity - what he's really saying is that manufacturers of small scale solar power generators might see a short lived boom in the near term.

Re:Subsidies?

[ShadowRangerRIT]

How many tax subsidies finance into your average power plant? How much are the indirect costs (ignoring CO2 emissions, let's just focus on locally increased health care costs from coal pollution, long term storage costs for nuclear waste, military adventurism for oil, etc.) of "traditional" fuels?

Re:Who pays for the infrastructure costs?

[presidenteloco]

FYI demand in summer in many states is highest with mid-day air conditioning, same time as solar peaks.

The grid as a whole needs to add much more storage, and long distance HVDC transmission lines, to balance intermittent power sources.

My general position is maybe start reducing the incentives for solar, EVs etc once we are at say 50% of where we need to get to in the level of penetration of these technologies. Until then, get any additional needed infrastructure revenue from gradually increasing carbon taxes.

Make sure there are both carbon taxes and affordable alternatives to burning fossil fuels.
That's the recipe for a successful transition of the energy system.

You and your grid can go dangle

[PopeRatzo]

The holy grail for solar and other renewables is "off-grid".

I'm not sure how you can look at this inexorable progress and not see that's where it's headed.

It's why there are already places where it's illegal to be off the grid.

I'll bet you that before we have ubiquitous self-driving cars we have homes that can produce their own power without the need for a "grid". My hope is that some day the grid will be the equivalent of the streetcar tracks that are still under the pavement in many cities. This is why I'm opposed to any large-scale public subsidy of the "smart grid".

Now that I think about it, my place has a "coach house" in the back. I've turned it into a garage, but there is still a hayloft in it. I've even left the block and tackle above the loft door for decoration. And that's just a few blocks from downtown Chicago. I hope I live long enough to see "the grid" become just another 20th century artifact. Of course, there are some powerful forces aligned to prevent that from ever happening.

Re:You and your grid can go dangle

[rahvin112]

Off-grid is what the power companies should actually be afraid of. Unfortunately they are in denial about that little tidbit. Off-grid is already cost competitive in Hawaii (mostly because their power is $0.35kwhr).

But battery prices are falling in tandem with solar panel prices. And I suspect any law banning off-grid will quickly be squashed by the courts as unconstitutional for many reasons. But off-grid represents a death spiral and would make every asset of the power company almost worthless. That death spiral is what they should fear, because every time they make being on grid with panels harder they are going to drive someone off-grid and the more people they do drive off grid the higher the shared costs will be which will drive more people off grid starting a death spiral that ends with bankruptcy and assets that are without value.

That death spiral is what Hawaii power is starting to deal with because of their mucking about with net metering. They've begun to change their tune but it could very well be too late for them. Hopefully it will serve as a lesson for all the other power companies before they walk down the same path.

Re:Who pays for the infrastructure costs?

[Khyber]

" a power source that's only producing cheap power during periods where demand is lowest?"

Yep, I can tell you don't live anywhere in the southern United States. Especially the southwestern areas.

Re:Hail resistant?

[dgatwood]

Are this things hail resistant? Lower prices are interesting only if won't be smashed by some pieces of ice falling from the sky

Generally speaking, yes. Anything complying with international standards is required to handle a 1 inch chunk of hail at terminal velocity (50 MPH). Many panels are rated up to 4x that, for added robustness, but I doubt those are the cheap ones. :-)

cost/price per kW hour comparison is nonsense

[ggpauly]

A solar installation is an investment. The proper analysis is return on investment. Current actual price before credits and rebates for a 4kW rooftop (16 panels, abt 25 m^2), installed, is about $16,000. This includes a substantial profit for the installer -- it should be available for less in a competitive market. There's a 30% US federal tax rebate, and here in North Carolina a 35% state tax rebate and a ~$1300 utility kickback. Assuming your tax situation allows you to take advantage of the credits, the net cost is about $6000. This will completely offset an annual electric bill of about $2000 - $2500. This is about 35% return on investment. Amortizing the net cost over a lifetime of 15-20 years for various components gives about 30% per year return. This return is tax free. This is an astoundingly good return. Berkshire Hathaway's total return over 49 years is 20% annually.

In other jurisdictions without the state tax rebate and utility kickback the tax-free return is 10 to 15%. Much better than the long-term return of any mutual fund.

Without any direct incentives the return is about 6%, tax free, very safe. CDs are currently about 1%.

Comparing the actual costs is the fair comparison. Apparently TFA omitted the actual government incentives on solar, while implicitly including them in the per kWh utility figures.

Rooftop solar has other benefits as well. Inverters are available that provide power during grid failure (during sunshine), and there are external benefits in replacing dirty coal or dirtier nuke power and slightly reducing the size and power of a monopoly corporation.

Re:cost/price per kW hour comparison is nonsense

[rahvin112]

Batteries are dropping in cost and increasing in capacity at about 20% per year right now. The Tesla gigafactory is expected to bring retail prices for a 85kwh battery pack to about $6000 where it's currently about $12k. For most residential homes an 85kwh battery pack is enough storage to provide power completely for more than 2weeks at full peak usage. With a gas heated home, the winter use of said battery pack would exceed a month without a single day of sunshine. Keep in mind the only time panels don't generate electricity is during the night and when the panels are covered. Even during a major storm, without snow, panels will continue to generate power during the day, just at reduced output. During the winter as long as the panels aren't covered in snow they will continue to generate power, and if tipped up to match the angle of the sun would generate better than 80% of the peak summer power.

Solar is a game changer and the retail price drops of panels will remake power generation, it's simply a matter of time at this point.

Re:cost/price per kW hour comparison is nonsense

[cbhacking]

Speaking as somebody who has spent year living on a sailboat where electricity was entirely provided by solar:

Even within a few miles of the equator, at local noon, a good rain squall will drop PV production to under 20% of its normal amount at that time. Later (or earlier) in the day it can easily drop all the way to effective zero - the charge controller eats a bit - until the sky clears. Of course, on the tropical ocean, "until the sky clears" is usually not that long. We (well, "they" now; my parents still live aboard but I do not) can run for a couple days (if fully charged) just living off the battery bank, though that would drop its charge lower than we like to let it go. On a really rainy day we might only get about 1/4 the normal production; if that keeps up for three days or so we'll run the engine for an hour to juice the batteries up.

As for winter, the biggest problem is not the angle of the sun (that is *a* problem, even if you tilt the panels, because of atmospheric losses... but it's not a huge problem) but instead is the length of the day. You might get 80% of summer noon on a sunny winter noon in some places (I doubt it would be true up here in the Pacific Northwet, and no, that's not a typo), but the boat has never been anywhere that *has* a "winter" so I can't speak from experience. However, on an average tropical Caribbean day, I measured meaningful power from 7:30 AM to 5:30 PM (10 hours total), with peak output around 1PM. That's only ten hours of electricity generation, and the vast majority of it occurred between 9:30 AM and 4 PM, for a period of only 6.5 hours (call it 2/3 of the day) where the panels produced more than 50% of their typical mid-day maximum. In Seattle in the middle of winter, we don't even get close to 10 hours of daylight; I wouldn't be surprised if we didn't get more than 6.5 hours of usable light at all. So, 2/3 as much time, multiply by 4/5 for lost brightness even at midday, and you're looking at barely over half the power per day in winter that you get from peak summer brightness. Take into account the fact that tropical days are shorter than summer days, and it looks even worse for a comparison of winter vs. summer.

Re:This has always been the problem..

[Anonymous Coward]

The price you receive has to be the value of that electricity to the utility. The calculation of that value is tricky because the utility has very high fixed costs related to infrastructure, operations, and generation; your electricity doesn't reduce their fixed costs at all. You might save them some variable costs of generation but you might also cause them to incur some additional management costs.

Solar power terminology

[Firethorn]

Charging a battery off of AC? Surely you mean RECTIFIER.

Nope, he said inverter, he was talking about a intelligent hybrid inverter like this Outback one.

The trick is that while it's called in inverter, that's only one of the things it does. Not only can it feed solar power to the grid, it can operate your home off of batteries, and if that isn't enough it can signal a generator to turn on(and off) as needs and power supply(solar AND grid) varies.

Re:Change is coming, so...

[Shakrai]

The power companies make a huge profit off of those solar users’ surplus power compared with what they would be paying for peaker plants. They can readily afford to absorb the infrastructure cost even if the customer is consistently producing more power than they consume.

In many (most?) States the power company isn't making any profit off this energy. Deregulation (a misnomer, actually they just changed the regulations) separated the supply/generation side of the business from the transmission side of the business. In New York State the utilities were forced to sell their generation facilities back in the 90s by the Public Service Commission. Customers are in turn forced to pick an "energy supplier" from a list of dozens of companies, the theory being that competition brings down prices. Of course this hasn't panned out in reality because electricity and natural gas are commodities; the price difference between the various suppliers is statistically meaningless even for customers that purchase large amounts of energy. I laid them all out in a spreadsheet once upon a time and the difference between the highest and lowest was less than 1%.

Of course, I digress. Bottom line, in New York State and many other States the utility isn't actually seeing any profit from your sale of solar energy. It goes back into the statewide electricity market and is bid on wholesale by spectators that then sell the energy back to consumers. The utility is only allowed to charge the usual transmission fees for this energy, which is a flat per kWh fee (with demand charges for larger commercial/industrial concerns) that doesn't vary based on the source of the energy.

If you want to make net metering competitive you'll have to attack this regulatory scheme that tried to improve a natural monopoly for a commodity by introducing false competition. Even at that it won't really be net metering because there's a non-zero cost associated with synchronizing your power supply with the grid. The fairest way would be to combine net metering with an additional flat monthly fee to cover the interconnection costs.

Of course, all of this is a moot point so long as the utility isn't actually allowed to touch your power but has to sell it into a virtual market that seemingly exists just to provide some middlemen with a profit opportunity.

The taxes are the biggest problem...

[MindPrison]

...at least in Scandinavia.

I often drool over the prices in China, cheap CHEAP and functional solar panels I could have gotten for pittens. But the taxes are so high that it evens out the score. Which is kind of strange since the government is subsidizing solar power anyway, but it's all lost on the import tax alone.

Won't happen if the utillities get their way

[jonwil]

Many utilities in the US are fighting rooftop solar through various means. The south-eastern states in particular are the worst for this.

Utilities are getting laws passed banning the "solar lease scheme" so popular in other parts of the US. And getting laws passed banning off-grid solar installs. And not providing net metering (either "you get paid for your excess electricity" or the "electricity you feed into the grid offsets what you use when the sun isn't shining but you wont get any money if you produce more than you use" model). And doing everything they can to push electricity generated from dirty black coal or nuclear reactors built to outdated 50s era designs instead of clean green energy.

PERMITS ! everybody forgets permits!

[bussdriver]

Many places in the USA have corrupted permit schemes. You don't pay a permit for an expert to verify your changes and protect the public-- you pay a % based upon the cost of the renovation. It is a home change TAX under another name and that is why you need permits for the most basic stupid things and why inspectors ignore checking most of the BS stuff; plus they are running around justifying the tax checking things that do not need it or enforcing the stupid rules (along with the good ones.)

I just got finished paying a 15% permit tax on top of the 7.5% sales tax for changes I made which were not inspected other than asking what the general plan was. On a huge solar installation that would be crazy just to have them make sure a few wires were connected properly.

Extrapolation story

[Tablizer]

About 10 years ago I studied a graph of the cost of solar versus conventional energy over time, extrapolated out, and saw them crossing in roughly 10 years. So, I invested in solar companies thinking they are going to take over conventional energy.

I got the crossing part right. What I got wrong is that those were domestic companies. Chinese companies generally have beaten domestic companies such that my stocks languished.

Predicting the future is not good enough; you have to predict the location also. Warren Buffet, I am not.