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The algae keep dying off at certain levels of scale.

Could you be more specific? Say, providing any information at all? If the algae die, you throw them in the centrifuge and start making biofuel. It's not a problem.

Nature colonizes open pools with an algae appropriate to the local climate, and whatever water you're using. Problems with algal die-offs are related to using special algaes, which are not necessary unless you're trying to use closed bioreactors.

Also, it has to be economical and its not clear that these types of algae based bio-fuels will be economical

Ye olde biofuels study showed that it would be possible to get economic results using seawater, though it would take up more space than using fresh water and adjusting its Ph. We have plenty of space for the purpose, though. You also have to leave the pools exposed for gas exchange, but that's how you get free algae colonization anyway. If you use closed reactors you also have to be all pissy about water quality; if you use open ponds, then the right algae for your water conditions just shows up like magic.

Yes climate change is real. But you don't seem to be reacting as if it is because you keep telling us to wait on unicorns instead of letting us solve the problem with nuclear.

The technology to do biofuel from algae was developed literally back in the 1980s (see PDF linked above) so there's no unicorns here, except maybe the political will to actually solve the problem.

Here, Look here and quit being a fucking idiot.

By the way, with geo-thermal, why does it have to be in remote areas? These are simple water wells like nearly all cities have.

It is less specific than you realize.
The entire western USA is great for geothermal, with lots of spots on the east coast as well.

Windbourne (moderating).

https://www.nrel.gov/gis/image...

Assuming you're American, it looks like you'd probably want to start on the western half of the country, but there are some okay sites on the east coast too.

The costs of many of the cheaper solar panels in use absolutely did NOT take into account all of the associated costs of producing them! One of the problems the industry has struggled with are all the cheap Asian panels on the market, often sold at below cost, thanks to government subsidies from China.

These circumstances applied only to panels from specific manufacturers for a fairly limited period of time. Most solar panels are not "dumped", not even from China.

I've never heard of these banks you speak of, who would allow a person to take out a larger home loan if they felt the person might use less electricity thanks to solar panels (or anything else)?

You may be unaware of it, but all banks consider the monthly expenses of every prospective loan recipient. Power very much factors in to their loan-making decisions, varying only by the demands of the local power company for money.

As for battery technology? I looked into that, but it's really too costly to make much sense in many situations. When the financials work out on it? It's usually only because that person's utility company decided to arbitrarily give discounted electric rates for power used at night ("off peak").

Which applies to quite a few people's houses. You may not be one of them, but millions upon millions are, including all of California. Even I am subject to time-of-day billing here in the Midwest.

A solar system installation similar to what I've got (a 7.64Kw sized setup) will typically cost a person around $34,000 to install.

That is indeed a stupidly high price, and it's largely an artifact of yesteryear's panel prices. When a solar panel cost $5/watt, installers could demand premium prices and know their demands would be lost in the noise. Now that panels are right around $1/watt (post Trump tariffs), installers charging double or triple what the equipment costs is really noticeable. It will change. It will obviously change. There were a whole helluva lot of people clambering around on my roof when I replaced my shingles after the last hail storm made a hash out of them, and it didn't cost me any $20,000. It cost half that, including the price of shingles. So $28,000 to install less than $8,000 of panels is ludicrous, and can't last.

Not only did that probably cost them FAR more money than they'll ever recoup

They didn't. Ground-mounted solar panels are far cheaper to install, even in this over-inflated installer market, and as stated above, installation price is the expensive part right now. Installing on the ground is incredibly easier than a roof-mount install. There's zero money or effort required to evaluate the load-bearing capabilities of the roof, since there's no roof. The insurance costs are dramatically lower since no one is climbing around on a roof. Even the time required is much lower since there are no logistics of dragging heavy, awkward panels up onto a roof to worry about.

It would be a really BAD idea to mandate solar panels in our state, and even worse for Missouri, where I was born and raised. They get less sun than we do.

Fact checking you, I see that NREL shows that Missouri is at least one category better than Maryland in almost every month of the year for solar insolation.

All of your opinions seem to be informed by your personal experience, which is obsolete or inapplicable. A decade ago, you were suffering early adopter tax, and definitely paying more for the non-financial benefits than any financial benefit you could hope to gain. Today and in the coming years, things are different and will become still more different. It will be (and already is) considerably easier to buy solar panels for the financial benefits, as well as the quality of life benefits.

You should definitely buy the geothermal heat pump system though.

You can figure out the impact of weather on PV panel production via something called capacity factor. That's the percentage of the panel's rated capacity it can actually produce over a month or a year. The NREL put out a website which incorporates weather data to calculate your expected capacity factor for any zip code in the U.S.

Solar sucks in Germany because of its latitude. Germany spans from about 43 to 53 degrees latitude, which only yields a capacity factor of around 0.11 (take the actual GWh generated, divided by installed MW * 8766 hours/year / 1000 MW/GW to skip over all the marketing BS). The continental U.S. spans from about 27 to 48 degrees latitude, and has an average capacity factor of 0.145.

Here's a link that speaks to that
http://www.nrel.gov/docs/fy12o...
In a nutshell, absent extreme temps in either direction, today's panels degrade very, very little over 20 years.

At or near the equator, UV will kill them at about 1-2% a year.
In very cold wet climates, snowload and wind degrade them about the same.

That doesn't make them a panacea of course. Non-distributability is the main problem. A tough not to crack.

AC, nope, wrong again. Really wrong.

Solar at Hawaii's location (96704 zip code) has a capacity factor of about 0.124

Different areas of Hawaii have dramatically different capacity factors. Some of the cloudiest and wettest places on earth are just over a mountain range from some of the clearest and driest. Just on the Big Island, Hilo has rain almost every day, while just 20 miles away is the Pohakuloa Plateau, in the rain shadow of Mauna Kea, which is arid desert.

How about it Tesla? Batteries, ready to spread solar power plant, multiplicity of connector types on a ship, always ready go in the case of a emergency.

Geothermal has a capacity factor of about 0.7. So the 38 MW the plant is rated for generates on average (38MW)*(0.7) = 26.6 MW.

Solar at Hawaii's location (96704 zip code) has a capacity factor of about 0.124 (this takes into account night, seasons, movement of the sun, weather, maintenance, etc). So generating 26.6 MW would require (26.6 MW)/(0.124) = 215 MW of installed nameplate capacity. That would make it the 18th largest PV solar plant in the U.S.

Assuming you're using commerical 180 W/m^2 panels, this would mean 1.195 million m^2 of solar panels, or 1.195 km^2 of panels alone. Or 67 Panamax-size container ships ( 66 meters x 49 meters) completely covered on PV panels to replace this single geothermal plant.

If you allow space to account for maintenance and tilt to the angle of the sun, the PV solar plants in this capacity range seem to cover about 5-10 km^2. So now you're talking about 280-560 Panamax-sized ships with solar panels on them to replace this single geothermal plant.

Or put another way, a single Panamax-sized ship with every upward-facing surface covered in solar panels would only generate (366 meters)*(49 meters)*(180 W/m^2)*(0.124) = 400287 Watts = 0.4 MW on average at this location. The average U.S. home uses 10,766 kWh per year, or an average of (10766 kWh) / (1 year) = 1481 Watts. So your one ship would be enough to power about 270 homes. There are already 10,000 people evacuated, which if you assume 4 per home is 2500 homes.

People *vastly* overestimate the power density of solar. Mobile solar is stupid unless you can drastically reduce your power consumption. Effective use of solar requires large areas of cheap land.

No. Fuel from algae is no where near commercial viability. Current costs are about $35 per gallon, a factor of ten too high, and little progress is happening.

That's only what it costs if you try to do it the frankly dumb way, where you do it in sealed reactors with bioengineered algae. The smart way is to do it in open ponds, and let nature colonize them. They figured this shit out at Sandia NREL in the 1980s . They had a program to study breeding superior strains of algae, but they got outcompeted by random colonization every single time. The total volume of lipids produced is higher when you just let some strain nature has already produced do the work. As a side benefit, everything that's not a lipid can go into the ABE process for making Butanol, a 1:1 replacement for gasoline which we would already be able to buy if BP and DuPont's company Butamax hadn't sued GE Energy Venture's GEVO to prevent them from selling it to us. (To save you time: The lawsuit was on the basis of a patent which should have been rejected for obviousness, which was furthermore developed at a public university, and therefore partly with our tax money.)

That's not "economies of scale", that's improved technology over time.

Still not providing anything to back up your opinions I see. Certainly it's easy to find citations saying the opposite:

A glut of low-cost solar panels—mainly manufactured in Asia—have pushed prices down in recent years.

Which directly contradicts your scarcity claims too (and not just recently, either). Yet demand and supply are both still dramatically increasing, with global installed PV increases up to 50% annually. It's hard to deny that scaled-up manufacturing like that contributes a lot to lower manufacturing costs.

As for the "analysts", judge for yourself. I'm going with "misguided", since we're well below that price already.

Depends on where you live. In Phoenix, $4160 of solar panel will produce roughly $1432 of electricity/year.

Plug in numbers here:

http://pvwatts.nrel.gov/pvwatt...

I used retail pricing here: https://sunelec.com/home/

Damn, they used to talk about payback in 15 years, not in 3.

I've found that many of the payback points to be outlandishly pessimistic. My costs for installing extra installation and changing to natgas for heating paid off in just a few years, when the "experts" were telling me no less than 10.

My biggest issue with going totally solar at home is that I have a spa, which even with a very efficient unit would stress the storage batteries. But I'm expecting even that barrier will fall, sooner rather than later.

Plug in numbers here:

http://pvwatts.nrel.gov/pvwatt...

I used retail pricing here: https://sunelec.com/home/

Estimating from the picture, they're laying out about 40 meters x 25 meters of panels (1000 m^2). At a nominal capacity of 160 W/m^2, that's 160 kW peak capacity.

Plugging in Puerto Rico's zip code (00901) into the PWatts calculator yields a 17.4% capacity factor (this factors in night, weather, movement of the sun across the sky, etc). Add in 14% system losses and 96% inverter efficiency, and you get an average actual power production of (160 kW) * (17.4%) * (100-14%) * (96%) = 23 kW. (Judging from the picture, actual production will be worse since the panels aren't tilted at Puerto Rico's latitude and pointed South to maximize exposure area. They're simply laid flat, tilted at a slight angle to shed rain.)

At a 25% ICE efficiency, you need a (23 kW) / (25%) = 92 kW generator to produce the same amount of power as this parking lot full of solar panels. 92 kW is about 120 horsepower. Basically an engine like the one under the hood of the small black car in the picture.

"But fuel!" you say. Diesel has an energy density of 35.8 MJ/liter. While generating 23 kW of power, the 92 kW generator is going to burn (92 kilojoules/sec) / (35.8 MJ / liter) * (3600 sec/hour) = 9.25 liters of diesel per hour (2.44 gallons/hr).

Assume these panels and batteries fit into a standard cargo container (2.43x2.59 meters x 12.2 meters long). If you fit a cylindrical tank into said container - 1.1m interior radius x 11 meters long (need some space for the generator), that could transport (pi) * (1.1 meters)^2 * (11 meters) = 41.815 m^3 = 41815 liters of diesel. That would be enough to operate the generator continuously for (41815 liters) / (9.25 liters/hour) = 4521 hours, or 188 days. A little over half a year.

It's been my experience that people vastly underestimate the amount of energy contained in petrochemical fuels, and vastly overestimate the amount of energy you can collect via solar. I'm not saying what Musk is doing is bad - if he lets them keep the panels to continue to power the hospital afterwards for decades, then it's most likely very good. But for emergency response, a generator is much more compact, requires less labor and space, and is logistically simpler to set up and operate.

Ooh, ooh, what if you actually did some research instead of just making stuff up?

Energy payback for solar panels is 1-4 years: https://www.nrel.gov/docs/fy04...

Energy payback for wind turbines is 5-8 months: https://www.sciencedaily.com/r...

Electric vehicles (or hydrogen vehicles if you're into that) don't make much sense if you run them off of coal, but they make a lot of sense if you charge them with wind or solar power. There is no other way to drive a car without emitting lots of greenhouse gases, gobbling up lots of scarce farmland (i.e., chopping down forests), or using up the surprisingly scarce supply of uranium.

• 700 MW of nameplate solar capacity multiplied by Levy County's solar capacity factor of 0.161 yields an average annual production of just 112.7 MW.
• By comparison, the scrapped nuclear plant's 2.2 GW multiplied by nuclear's capacity factor of 0.9 yields an average annual production of 1980 MW.

So this 700 MW of solar power represents just 5.7% the capacity of the scrapped nuclear plant. Guess where the other 94.3% of energy production is going to come from (hint: its initials are FF)?

To replace the nuclear plant entirely with solar, they'd have to build (1980 MW / 0.161) = 12,300 MW of panels. That's more than 8x larger than the largest existing solar plant in the world, more than 20x larger than the largest existing solar plant in the U.S. At the optimistic cost of $1/Watt, those solar panels (never mind the supporting infrastructure) would cost $12.3 billion. The nuclear plant was only going to cost $7.65 billion. They killed it because of regulatory delays.

Utterly false. At worst it's 4 years out of a 30 year lifetime. At best it's a year. http://www.nrel.gov/docs/fy99o...

Assumes they have a really short lifespan. Basically they are using manufacturer's estimated lifespan of 25 years, when in truth, these things do not stop working. No moving parts, hermetically sealed so no water, insects, or even air gets in, low electrical voltage. The most common cause of destruction is something hitting them - lightning bolts, hail, baseballs. They can theoretically last for centuries, not 25 years.

Wrong. Silicon plate panels, i.e., the ones nobody wants to purchase anymore because they're ungodly expensive in comparison to alternatives, degrade at 0.5-0.7% of power capacity per year.

Thin film panels, i.e., the ones everyone is currently buying due to cost advantages, degrade at 1-1.5% of power capacity per year.

After you've lost 20% of your capacity and can no longer satisfy your design load, you're not going to be happily touting how you can still get power out of your panels.

Who says? The NREL, based upon about 1700 data points (Fig. 2 of linked report).

Don't sell me bullshit either.

Well that seems to be at odds with what the IEEE found - http://spectrum.ieee.org/green...

I'm not sure what you mean by "at odds," since the IEEE Spectrum article doesn't even discuss energy payback time. Here's an article showing an energy payback time of 3.7 years for a typical home rooftop PV system, or 2 years for a slightly more efficient panel: http://www.nrel.gov/docs/fy04o... Graph 2 shows a panel produces 20 times more energy over the 30-year lifetime (which is the PV panel typical warranty) than the energy used to produce it and mount it on the roof.

That's roughly comparable to the values shown in other sources. Here's a review paper saying that the Energy Return on Investment (EROI) is from 8.7 to 34.2 (depending on things such as where it's located, and what technology is used): http://www.sciencedirect.com/s...

The IEEE article is a caution saying that the Chinese module manufacturers don't necessarily pay attention to the environmental effects of manufacturing. This is a problem with any manufacturing, though, not particular to solar panels. They export about 180 billion dollars worth of stuff to us every month, so if you're worried about the environmental impact of Chinese manufacturing, that's laudable, but solar panels aren't even one percent of that.

Based on a meta-analysis, current PV systems have energy payback times of about 3-4 years. But that's unlikely to be accurate. Subsidized payback periods for PV systems are about 7 years, and unsubsidized payback periods are about 15 years, and both PV and non-PV costs are dominated by energy inputs.

Seattle gets about 3.7 hours per day average insolation. It doesn't make sense to put them there until you run out of space in AZ and California. Your roi is 2x higher in those places. Worse than that, it doesn't provide energy in the winter when it's needed most. I have a house there and my summer electric bill is next to nothing.

http://rredc.nrel.gov/solar/ol...

This is a VERY boring trope. If you only want completely finished consumer grade tech then stop reading /. and go read a product catalogue, maybe on paper, and stop wasting our time on your public masturbation/trolling.

For example, on another topic:

https://slashdot.org/comments....

And yes those more efficient PV cells are emerging in several different directions depending on application, and I'm been installing some of them. In terms of W/$ (thus J/$) I've recently put up stuff that cost me 1/10th of what went on my roof a few short years ago.

So if you would bother using your favourite search engine or paying attention to the field rather than whining, you'd know about them. The improvement in PV has been a science and engineering wonder possibly only eclipsed by CPU performance.

And here is probably the best-known pretty chart from NREL, easily found with a search for (wait for it)... "chart of solar PV efficiency":

https://www.nrel.gov/pv/assets...

Damon

I can buy solar panels retail now retail for 14cents/wattp. Before Germany started building solar everywhere it was 10x more expensive and while Germany is still paying on their solar systems, mine will have already been paid off and earning me money. Photovoltaic (PV) Pricing Trends: Historical, Recent, and Near-Term Projections (pdf). See also Swanson's law. Even at this stage solar is not a significant amount of energy at somewhere around 1-3%.

What about at night?

Fortunately the wind blows at night. Here is a wind resources map for the United States. Lots and lots of consistently windy areas. Wind is cheaper than solar currently and in nine out the ten nations that top the renewable energy charts, there is more wind capacity than solar, and this is likely to remain the case.

With the use of high voltage DC transmission lines (a technology that has been in use since 1930) electricity can be shipped coast to coast with minor losses. 800 KV lines can transport electricity from one coast to the other with about the same losses as existing grids, about 6%. Constructing a national long distance electrical "highway" makes most of the "problems" perceived with renewable energy disappear. Just like now, there is not going to be just one source of power in the future, so solar does not have to do it all.

Even is solar "only" supplies the daytime peak load, this is half of the total electricity demand. In North America it is convenient that 40% of the entire U.S. population lives on the Eastern Seaboard, so that when it has its evening demand peak, the sunny west is three hours earlier and would still be producing a lot of solar electricity. Then there are proven power storage technologies like pumped water storage. Just considering existing pumped storage capacity, and capacity expansion that has applied for permits, we are looking at 76.7 GW of PS capacity in the U.S. which is 7.5% of U.S. peak electricity demand.

Also, if you look at that paper, Fig 7 shows the only ones up around 30% are in irradiances of >7. If you looks at non-tracking in areas with irradiance less than 7, you'll see it maxes out at 25%. As you can see from an irradiance map, zones above 7 are pretty scarce.

http://www.nrel.gov/gis/images...

In 2014, the United Nations Intergovernmental Panel on Climate Change found that nuclear power has the lowest lifecycle emissions of any electric generating technology, except for wind energy.

The IPCC accepted data on this subject from Vattenfall, a company with heavy investments in Nuclear power.

The Department of Energy’s National Renewable Energy Laboratory released its analysis of life-cycle emissions in 2012 and concluded the following about nuclear:

Thank you. I appreciate you sending information instead of hyperbole, I'll check that out.

In 2014, the United Nations Intergovernmental Panel on Climate Change found that nuclear power has the lowest lifecycle emissions of any electric generating technology, except for wind energy.
                      * Graph of 2014 IPCC lifecycle emissions findings.

The Department of Energy’s National Renewable Energy Laboratory released its analysis of life-cycle emissions in 2012 and concluded the following about nuclear:
                      "Collectively, life-cycle assessment literature shows that nuclear power is similar to other renewables and much lower than fossil fuel in total life- cycle GHG emissions."

http://www.nrel.gov/news/featu... The wind turbines in Antartica seem to be going OK and its a lot colder there.

We've gotten a bit off track here.
I originally responded to a post which proposed making H2 from electricity, storing it and then converting that back to electricity. I pointed out that this is very inefficient (you only recoup about 30%). This is a very poor method to store electricity. I also pointed out that there is no need for long term battery electricity storage since short term fluctuations in wind, solar, hydro tend to even out. Recently published models of electric production from renewables have show that it is possible to support the grid entirely with renewables.
http://www.worldbank.org/en/ne...
http://www.nrel.gov/electricit...

CH4 production and use for heating is a different subject.

This suggests otherwise: http://www.nrel.gov/analysis/s...

Do you have a source?

Yes, plants are listed at full capacity ratings in MW, but that does not tell us the cost of energy, so that is not used to compare the cost of energy. You CAN compare capacity, but that is of little use, on its own, when comparing different energy sources because of the exact variables you stated. And while plants are and will always have KW capacity ratings, the measure for comparing energy cost is, has been, and will always be $/MWh.

Which is why any credible reference for energy cost uses $/MWh.

http://www.nrel.gov/analysis/t...

https://www.eia.gov/forecasts/...

https://en.wikipedia.org/wiki/...

http://www.renewable-energy-ad...

I could provide many more examples. Maybe you should write to all these and tell them they don't know what they are doing. Note that some of these references are renewables organizations. Now, please provide one credible reference that uses $/MW to compare energy cost. (Not some article written by some ignorant yahoo). But instead, I expect you will just blabber on about how using $/MWh is some sort of anti-renewable conspiracy.

And, as has been discussed already, you and I both live in places where grid power is stupidly cheap in comparison to other places. Just because Solar doesn't pencil out for you or me, doesn't mean it is bad for everyone. It has something to do with incredibly small sample sizes when doing a statistical study.

Solar does work in Texas, but perhaps not in your municipality because your energy company isn't putting the screws to you like other ones do. It works in Ohio too, but not around the Cincinnati area because we have barges loaded with coal floating past downtown every day, delivering coal to the rest of the nation (and world). However, our two data points don't make an accurate set to analyze.

Fortunately, there are some folks that have far more data than that, and have done it properly. If you look on pages 13 and 14, they've done some nice maps of the US where they've indicated where the break-even cost on solar is depending on the installed cost per watt, and if time-of-use rates applied. At $3/watt, it's break-even everywhere except the Pacific Northwest, some bits of Appalachia (coal country), and southeast Missouri (on the Mississippi, where all the coal form coal country is shipped).

Are you really trying to tell me that because Solar doesn't pencil out for you, that everyone else that researches this stuff is wrong?

An average of 5 peak sunlight hours per day puts you the same as California, Nevada, Utah, and Colorado - all of which are installing solar as fast as possible.

CA is installing 40% of the national distributed solar, largely due to large tax incentives within the state.

The next 9 states are another 44%, for a total of 84% of the national solar installs in just 10 states.

Why is it that you can't understand it is all about the tax incentives that make this work, without them it simply doesn't.

It's fair to say that you get super cheap energy from the grid - I know I do. But to say "we only get 5 hours of sunlight" is complete bunk.

I looked up this past month's bill, it was almost exactly 9.5 cents per KWh and that includes all taxes and fees.

Where I live, we average 5.5 hours of sunlight a day annually. Oh sure it is 10 hours some days, but it is nothing other days. Actually it may be less than that, I just went here:

http://pvwatts.nrel.gov/pvwatt...

and did a quick calculation, it says based on the angle of my roof, I would get a net effective 4.68 hours of solar radiation per day for a 10KW system. It would save me an estimated 13,100 KWh per year, or about $1,244.50 which is even less than the estimates from the solar power installers.

Spending $25,000 out of pocket after tax credits to save $1,244.50 a year is a really bad investment, considering the risks. It assumes net-metering never goes away, which if it did, would remove much of that savings. It also assumes that for 20 years, ZERO maintenance would be required to the system. Oh sure the panels likely are fine, but the inverter won't last 20 years and there is always something to fix now and then.

Your -30% isn't really data, it's just a single point linked to an inaccurate measure. Literature (e.g. http://www.nrel.gov/docs/fy11o...) usually mentions degradation rates of -0.5%/year, so about -10% in 20 years.
But talking about optimism : Your glass is still less than 1/3 empty, so it's still more than 2/3 full ;)
Even -30% in 20 years is actually not so bad for a system that delivers free power without maintenance.
If you clean your modules, check the cables+junction boxes and replace your inverter, you'll probably get much more than 70% of the original output.

> I believe (but I may be wrong) that the common commercial panels these days use three-layer cells.

Only in space, where the efficiency gain is worth a lot more. Terrestrial panels are typically multi-crystalline silicon, which is cheaper to make than mono-crystalline. Some places use mono-crystalline, because it has a bit higher efficiency, and therefore higher output when space is limited, such as on a rooftop. You can track the best "research cell" efficiencies at http://www.nrel.gov/ncpv/image... (the chart is frequently updated). Between research and mass production at the lowest cost there is a variable time delay, usually years.

This isn't the first time us Brits have come up with solar for cloudy days. See:
British scientists develop solar panels which work better on a cloudy day [March 2014]
Both articles lack details about the efficiency in diffused light conditions.

Researchers from the University of Surrey in the U.K. studied the eyes of moths to create sheets of graphene that they claim is the most light-absorbent material ever created.

I doubt this very much, the best solar collectors will collect 46% of light, but of course they don't come cheap, current cheap cells are the ones collecting up to 15 to 22% of light.

Cell Efficiency Chart (jpg)If the researchers had created solar collectors with more than 46% efficiency then they would say what the efficiency is and have it verified and it would be big news.

ORLY?

http://www.nrel.gov/gis/images...

That's what we feel too. When wind units are allowed to bid negative offers, because their operations costs are offset by government-funded renewable energy credits, it distorts the market to the point that traditional generation cannot compete. This is why the "expiration" of the Renewable Energy Production Tax Credit was such a big deal, in that everyone had to "break ground" by 12/31/2014, which is why there is a flood of windpower energy this year. You cannot build transmission this fast.

http://energy.gov/savings/rene...

http://www.nrel.gov/electricit...

https://www.fas.org/sgp/crs/mi...

Molten salt is terrible for electricity storage.

Thermal energy capacity: 0.13 kWh/kg
Electrical conversion efficiency: 25% at best
Electrical storage capacity: 0.03 kWh/kg
Amount of mass to store 12 kWH (one household overnight): 400 kg
Amount of mass to power a large city overnight (1 million households): 1 Empire State Building

Sodium-sulfur battery electrical storage capacity: 0.5 kWh/kg
Charge/discharge efficiency: 80%
Useful storage capacity: 0.4 kWh/kg
Amount of mass to store 12 kWh (one household overnight): 30 kg
Amount of mass to power a large city overnight (1 million households): 1 large submarine

Both systems use cheap, common materials, both systems are proven reliable over decades, but you get about 10 times as much energy storage when you use chemistry.

Molten salt is terrible for electricity storage.

Thermal energy capacity: 0.13 kWh/kg
Electrical conversion efficiency: 25% at best
Electrical storage capacity: 0.03 kWh/kg
Amount of mass to store 12 kWH (one household overnight): 400 kg
Amount of mass to power a large city overnight (1 million households): 1 Empire State Building

Sodium-sulfur battery electrical storage capacity: 0.5 kWh/kg
Charge/discharge efficiency: 80%
Useful storage capacity: 0.4 kWh/kg
Amount of mass to store 12 kWh (one household overnight): 30 kg
Amount of mass to power a large city overnight (1 million households): 1 large submarine

Both systems use cheap, common materials, both systems are proven reliable over decades, but you get about 10 times as much energy storage when you use chemistry.

Even though I know that a solar panel will never make the energy back that was used to produce it...

That hasn't been true for a long time.

Nor are they the most efficient panels by a long shot. Panels for space use can go up into the 30-40% range (multi-junction). Perhaps these are the most efficient thin film crystal panels, or scalable-manufacturing single crystal? The article doesn't say.

Solar panels are not heat engines, so Carnot cycles are irrelevant. The best cells have now reached 46% in the lab ( http://www.nrel.gov/ncpv/image... ). The high efficiency cells use multiple types of semiconductor stacked up. Each type is optimized for a different wavelength. Note that cell is not the same as panel, because less than 100% of the panel area is cells. Multi-layered cells currently are used on spacecraft and in concentrator modules, because they cost more than single-layer cells to produce. The efficiency gain only makes sense for those applications.

I'm getting a 7kW kit with microinverters (fuck string inverters). According to PVWatts, which my state uses to decide how many energy credits to give you for generation (rather than reading your actual generation statistics) for arrays under 10kW, I'll generate 9,842kWh/year on average, saving $1772 in electricity costs (including transmission fees, per-kWh taxes, etc.), plus about 10 SRECs selling for between $150 and $200 each (they're selling for $200 now!)--another $1500.

With the 30% ITC and the $1,000 MD grant, the ROI is 2.5 years. $8,000 base cost just about, $3,000 yearly return.

I used the National Renewable Energy Laboratory's System Advisor Model (SAM) tool when I designed my 16kWdc rooftop array. You can download SAM from the NREL site. They also have a web-based tool called PVWatts that is far less detailed, but is definitely easy to use and produces a very reliable estimate if you are thinking about a PV array.

For what it is worth, rooftop solar is facing stiff opposition from utility companies and energy producers because it directly affects their bottom line. Changes in net metering regulations that favor the existing energy production infrastructure over locally produced alternative energy are becoming more common as the fossil fuel industry fights to retain the status quo. Without going on a rant about it, I watched my seven year ROI on a $42k project evaporate because of changes to Arizona's net metering regulations put in place this year by the bought-and-paid-for-by-Koch Industries Arizona Corporation Commission.

I used the National Renewable Energy Laboratory's System Advisor Model (SAM) tool when I designed my 16kWdc rooftop array. You can download SAM from the NREL site. They also have a web-based tool called PVWatts that is far less detailed, but is definitely easy to use and produces a very reliable estimate if you are thinking about a PV array.

For what it is worth, rooftop solar is facing stiff opposition from utility companies and energy producers because it directly affects their bottom line. Changes in net metering regulations that favor the existing energy production infrastructure over locally produced alternative energy are becoming more common as the fossil fuel industry fights to retain the status quo. Without going on a rant about it, I watched my seven year ROI on a $42k project evaporate because of changes to Arizona's net metering regulations put in place this year by the bought-and-paid-for-by-Koch Industries Arizona Corporation Commission.

I used the National Renewable Energy Laboratory's System Advisor Model (SAM) tool when I designed my 16kWdc rooftop array. You can download SAM from the NREL site. They also have a web-based tool called PVWatts that is far less detailed, but is definitely easy to use and produces a very reliable estimate if you are thinking about a PV array.

For what it is worth, rooftop solar is facing stiff opposition from utility companies and energy producers because it directly affects their bottom line. Changes in net metering regulations that favor the existing energy production infrastructure over locally produced alternative energy are becoming more common as the fossil fuel industry fights to retain the status quo. Without going on a rant about it, I watched my seven year ROI on a $42k project evaporate because of changes to Arizona's net metering regulations put in place this year by the bought-and-paid-for-by-Koch Industries Arizona Corporation Commission.

http://pvwatts.nrel.gov/

You happen to have a citation on that? Because mine says the opposite.

Power companies maintain spinning reserve even when there isn't any solar/wind power. Fairbanks doesn't have significant amounts of solar or wind power, but they have the BESS irregardless. It enabled them to keep generation facilities at a lower state of readiness while still reducing power outages when a generation source goes off line(such as the inter-tie with Anchorage).