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Bigger, Cheaper Solar Cells
Posted by
Soulskill
on Sat Aug 09, 2008 11:02 AM
from the not-quite-DIY dept.
from the not-quite-DIY dept.
Phenombecile800 writes "First Solar, a start-up from Arizona, is making photovoltaic cells at a fraction of the usual cost. Their secret: increasing the light-catching area 'from postage-stamp to traffic-sign dimensions,' reducing the manufacturing time to 1/10th of the competition's, and thinning the active element to 1/100th the usual thickness over a glass substrate, which enables the production of large panels. IEEE Spectrum provides some technical details about the production process. 'Glass is placed on rollers and fed into the first chamber, where it is heated to 600 C. Then it is transferred into the second chamber, which is full of cadmium sulfide vapor, formed by heating solid CdS to 700 C. The vapor forms a submicrometer deposit on the glass as it moves through this cloud, after which a similar process in a third chamber adds a layer of micrometers-thick CdTe in about 40 seconds. Then a gust of nitrogen gas rapidly cools the panels to 300 C in a fourth chamber, strengthening the material so that it can withstand hail and high winds.'"
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The old green question (Score:5, Interesting)
It's probably unanswerable, but I wonder how much energy it takes to make these cells, and how long it takes for them to offset that?
Re:The old green question (Score:5, Insightful)
What everyone seems to be waiting for is a cost-per-watt that is low enough so that ordinary people will decide to start buying them in large quantities without government subsidization. Suppose you're having a new house built: if you could install a ten or fifteen kilowatt solar plant and inverter for ten grand, you might figure it's worth it to borrow a little more money from the bank. I think we'll see more of that as our distribution grid continues to deteriorate and utility power becomes less and less reliable.
Parent
Re:The old green question (Score:5, Informative)
What everyone seems to be waiting for is a cost-per-watt that is low enough so that ordinary people will decide to start buying them in large quantities without government subsidization.
You won't see it from FSLR, unfortunately. Their output is currently (no pun intended) earmarked for commercial ventures only, no retail/residential sales. Pity. Hope that changes.
Parent
Re:The old green question (Score:4, Insightful)
That's to be expected, selling to commercial or retail buyers allows them to sell in much higher quantities, plus those buyers are more likely to need larger ones as well.
Ultimately, whomever they sell to, if you're living in an area where the panels are being installed you're still going to be getting benefits from the advance, even if it's a small reduction in the price of electricity and pollution.
There isn't likely any reason why somebody couldn't buy in bulk to provide to home owners, it looks to me far more like a disinterest in direct marketing than a wish to not allow small scale sales.
Parent
Re: (Score:3, Interesting)
there's plenty of motivation to eat that delta in profit, especially for a public company as in this case.
And said profit can be used to expand the company- increase production, research increasing efficiency and decreasing costs, not to mention paying back the investors.
Making mad money can also encourage others to get into the industry.
After all, the market for $2/watt panels is likely 4X that of $4/watt panels. And orders of magnitude more if they can manage to make $1/watt panels - installed, since tha
Re:The old green question (Score:4, Insightful)
Parent
Re:The old green question (Score:5, Insightful)
And that is exactly what you need in countries that don't have a subsidization program. In the USA, I can see some of the more "green" states like California providing subsidies, but the current federal government seems more inclined to support the petroleum industry. How much change Obama would bring remains to be seen.
So a cost-per-watt that doesn't need subsidies will be an important step forward in making solar power widespread. A deteriorating distribution grid will also do its part, especially if the cost-per-watt-hour of batteries decreases. Here I guess that new Li-Ion chemistries will do their part when more manufacturers make them and competition kicks in.
Parent
subsidies from private industry (Score:3, Interesting)
The biggest source of solar subsidy for homeowners in Arizona is the power companies themselves. They'll pay for roughly half of your installation. My guess is that this is just smart infrastructure investment for them-- you foot half the cost and handle the maintenance, but they know the panels aren't moving once they're installed.
Re:The old green question (Score:4, Informative)
More likely these installations will use the good old Nickel-Iron battery [wikipedia.org]
In many respects the Nickel/Iron battery was almost "too good." A battery that lasts for decades in many cases can outlast the equipment that it was originally designed to power. So from an economic standpoint lead acid, NiCd and other technologies have been deemed "good enough" and are the predominant technologies in use today even though they do not last as long as a Nickel/Iron counterpart. Nickel-Iron battery [wikipedia.org]
These batteries do have limitations that make them less suitable for vehicular use such as
low specific energy, poor charge retention, and poor low-temperature performance.
since a residential or commercial solar pv installation is stationary, specific energy isn't a concern, the charge will only be needed to pull you through a night or a couple cloudy days and the batteries will be stored in a climate controlled area so they should be awesome for the task.
Parent
Re:The old green question (Score:5, Informative)
A couple of things to keep in mind here:
Parent
Re: (Score:3, Interesting)
Oil != electricity (Score:4, Informative)
My dispute with this line of reasoning is that we use an insignificant amount of oil for electricity generation purposes. So your three war argument is off-topic.
The significant hydrocarbon sources for our electricity is coal and natural gas.
Of which, receive some of the most marginal amounts [wsj.com] of subsidy in the industry
As for being used on cars and such - solar doesn't have enough density to realistically power a car via an on-car array.
Parent
financing solar (Score:4, Informative)
Suppose you're having a new house built: if you could install a ten or fifteen kilowatt solar plant and inverter for ten grand, you might figure it's worth it to borrow a little more money from the bank.
More [resnet.us] and more [betterworldmortgage.com] mortgage companies are financing solar energy systems. Some allow borrowers to borrow more because of such systems. With an alternative energy system installed living costs are reduced so they are willing to lend a higher percent of the what the borrower's income would suggest.
Of course the mortgage crisis [bnet.com] does have a negative impact, it has hurt solar businesses [investorvillage.com].
Falcon
Parent
Re:The old green question (Score:5, Interesting)
It's probably unanswerable, but I wonder how much energy it takes to make these cells, and how long it takes for them to offset that?
We can answer anyway without even RTFA. The summary says that the cells are made out of glass (not hewn out of a crystalline ingot of silicon). Assuming 10% efficiency and 20% availability of sunlight (due to weather and geometry), you get approx 20W/m^2, or 1 kWh every two days.
Given that glass beer bottles cost a few cents each, a square meter of glass probably takes no more than a few dozen kWh of energy to produce. Even if the vapor deposition doubles or triples that, you still would end up with an energy surplus after just a couple of months of operation.
Parent
Re:The old green question (Score:4, Insightful)
> Given that glass beer bottles cost a few cents each, a square meter of glass probably takes no more than a few dozen kWh....
This isn't beer bottle glass though. Beer bottles are generally blown out of recycled glass, while panel glass is produced by floating clear glass (generally not recycled) floated on molten zinc. Point being that the process is considerably more energy intensive than an equivalent number of beer bottles.
Now, they probably could get away with cheap recycled glass (i.e. brown, like beer bottles) and use a low power continuous vapor deposition system if/when these get mass produced, but in their current state I'd wouldn't be surprised if the break-even point is around 1.5 years.
Parent
Re:The old green question (Score:4, Insightful)
Why is that? I mean once you have high temp water and you need it to be low temp water, and you have more water that needs to be high temp water why not transfer the energy from the now distilled water to the needs to be distilled water. Energy requirements in that case are equal to energy lost to transfer efficiency constraints.
The principle is well known and called "regeneration" - you pass the incoming fluid through a heat exchanger with the outgoing fluid. For instance it's mentioned here [blogspot.com] in connection with the important Haber-Bosch ammonia process. It's also used by penguins to keep them from losing heat from the bloodstream through their feet! If the engineers are not doing it, they are really really poorly educated, or they have some decent reason. I suspect mainly the latter...
Parent
Re: (Score:3, Insightful)
Re: (Score:3, Insightful)
No objection to a solar powered solar panel plant. (Score:4, Interesting)
Actually, the biggest portion of glass manufacturing is, of course, heat. You wouldn't want to use 10% efficient cells to produce electricity that goes directly to an electric resistance element to make that heat.
Instead, you'd want to build a solar furnace - using mirrors and lenses and such you can get 90% efficiency, and using panels even cheaper than this.
The trick would be the substantial start-up time in the mornings. Due to the heat levels involved, you'd be wasting a lot of energy each day heating the equipment up again.
So either you have to find a solution for this, or use natural gas or whatever during the night to keep production up. This isn't bad as long as you still get more energy out of the resultant panels, etc...
Parent
Re: (Score:3, Interesting)
What you need is a thermal storage system and good insulation of your hot gear. Since they're talking about using molten salt as well as other substances like hard pitch (incredibly high boiling point) as thermal storage to allow solar power plants to produce power over 24 hours, I'd say the solution to the problem is at hand.
And you're
Re:The old green question (Score:5, Informative)
The head of Applied Materials solar division said in a talk at Stanford last year that their solar panels took two years of their own output in energy to make. They hope to get the energy breakeven point down to six months. He said the sputtering process they use in coating is energy-inefficient, and they're trying to develop something better.
Total installed energy cost is probably higher. Home solar installations are about 50% installation cost. The big open-field installations are cheaper; they have economies of scale.
Forbes mentions that Mojave Desert real estate is becoming more valuable because many companies want to build solar facilities there. There's plenty of space in California, Nevada, and Arizona for solar panels.
Mike Splinter of Applied Materials (the largest maker of semiconductor fab gear) likes to say "Everybody else's costs (in the energy business) are going up, and ours are going down. We're nowhere near market saturation. This is a great business for us."
Parent
Mojave Desert (Score:4, Interesting)
Forbes mentions that Mojave Desert real estate is becoming more valuable because many companies want to build solar facilities there.
It's not just solar farms that are sprouting up in the Mojave, wind farms are as well. Actually there's one wind farm that virtually sat there silent [commondreams.org] back when CA had those rolling blackouts because the transmission capability wasn't there.
Falcon
Parent
Re:The old black question (Score:5, Interesting)
Parent
Re:The old black question (Score:5, Funny)
I think you may be seriously underestimating the deliciousness of nachos.
Albeit not from the 7-11.
Parent
Arizona! (Score:4, Interesting)
Well, a smart idea would be to move all of our high tech manufacturing to the hottest deserts we have. You can build earth sheltered factories to save on A/C, cover the roof and surrounding area with solar panels for virtually unlimited electrical supply, bury some flywheel energy storage to keep necessities going at night. If solar panels turn out to be unsustainable, simpler thermal power plants could be used.
You have an endless supply of sand for glass and silicon. You make non-perishable goods that can be moved out slowly and efficiently (solar/thermal powered electric rail or whatever). To make it really sustainable you could use the same transportation to import recycled or recyclable plastics for the rest.
Our current answer is using fuel that's guaranteed to run out. We should shop direct for our energy.
Parent
Re: (Score:3, Interesting)
Well, a smart idea would be to move all of our high tech manufacturing to the hottest deserts we have. You can build earth sheltered factories to save on A/C, cover the roof and surrounding area with solar panels for virtually unlimited electrical supply, bury some flywheel energy storage to keep necessities going at night. If solar panels turn out to be unsustainable, simpler thermal power plants could be used.
You're forgetting one thing: water
Hi-tech industry is insanely thirsty and water is the one thing you will not be finding in the dessert.
Re:The old green question (Score:4, Insightful)
It's probably unanswerable, but I wonder how much energy it takes to make these cells, and how long it takes for them to offset that?
From my understanding, current systems (with tax rebate) pay for itself in 10 years at current prices from the end users standpoint.
However, if say conventional energy prices double again in the next 5 years, then solar panels will have payed for themselves in a much less of a time frame even without the rebate.
I think its a misnomer about how much any energy it takes to make something because the price of energy itself fluctuates with time. Lets say it might take 10 barrels of oil to create one solar panel that produces 1 barrel of energy a year saving which will pay itself off in 10 years but if oil costs $100 last year and $200 in the next 5, then your $1,000 system now is worth $2,000 and your system is creating the equivalent of $200 worth of energy saved a year therefore paying itself off in 5 years.
Hope that made sense. I'm sure the numbers are no where like that though.
Seeing that the price of sunlight is less volatile than the price oil or coal, one could really gamble that peak oil will make any investments into solar pay for itself in short order in the next decade.
Parent
Re:The old green question (Score:5, Informative)
Article gives the size of the glass, and some temps, so it may just be answerable. Googling for: how much energy does it take to manufacture glass, 5 hit (no direct link since its a f***in word doc)
The Recipe For 1 Ton Of Glass (Resources)
1300 Pounds Sand
400 Pound Soda Ash
400 Pounds Limestone
150 Pounds Feldspar
24000 Gallons Water
4400 KWH of Energy
So, 4400 KWH per ton.
How much do the panels weigh?
(.6 m) * (1.1 m) * (.5 cm) * (2 500 (kg / (m^3))) = 8.25 kilograms
(8.25 kilograms) * 4 400 (KWh / ton) = 144 Mj
Apart from making the glass, there is heating the glass, heating the cadmium sulfur and telluride, mining all those chemicals, etc.
Glass specific heat is .84 J/g K.
(.84 (J / g)) * 8.25 kg * 580 = 4 019 400 joules
So I've calculated 148Mj for the glass manufacture and heating.
Ignoring the cadmium, sulpher, telluride chemical mining, what do you get out of it?
(85 watts) * 25 years = 6.7 Ã-- 10^10 joules
How much coal is that? http://www.newton.dep.anl.gov/askasci/eng99/eng99187.htm [anl.gov]
6.7E10 joules) / (4.11E6 (joules / pound)) = 7 400 kg
Remember how I ignored the energy of mining those chemicals?
How does the energy compare for mining the GRAMS it would take to deposit a film of telluride compares to the energy for mining TONS of coal.
The answer to what you did ask, at least for the glass + heating, is pretty easy to answer:
(148E6 / 85) * s = 480 hours. Less than a month.
Parent
FFS, do you want something for nothing? (Score:4, Insightful)
How much energy does it take to maintain an oil platform in the North Sea? How much energy did it take to build Hoover Dam? We're not going to get a magic machine that gives us energy and costs none to build. Even if the answer is "years and years," the point is that we're trading dirty energy for clean energy, so it's worth doing.
Parent
Cost of manufacturing (Score:3, Informative)
Not based on this new technology, but here's the info:
From http://www.nrel.gov/pv/pv_manufacturing/cost_capacity.html [nrel.gov]
National Renewable Energy Laboratory
Photovoltaic Research - PV Manufacturing R&D
Cost/Capacity Analysis
The PV Manufacturing R&D Project Coordination Team measures and tracks the progress of the Project's impact on module cost and production capacity. The module-manufacturing partners voluntarily provide the team with two types of critical information: direct costs of module manufacturi
Re: (Score:3, Interesting)
Well, if they were made by solar-powered plants, we wouldn't have to worry about that,would we?
their tech (Score:5, Informative)
Cadmium Telluride is also a direct bandgap semiconductor which yields more watts per kg than the indirect bandgap semiconductor materials. Solar cells become less efficient at converting solar energy into electricity as their temperatures increase but Cadmium Telluride is less susceptible to cell temperature increases than traditional semiconductors generating relatively more electricity under high ambient temperatures. It's also more efficent at converting low and diffuse light to electricity more efficiently than conventional cells under cloudy weather and dawn and dusk conditions.
They also have a recycling plan in place for the lifetime of the product - somewhat at odds with the traditional landfill methods of yore. But, no retail. They don't sell to individuals and only deal with utility companies. Finance trivia: Their stock has grown spectacularly since the IPO and there is a large investment from the Walton family (insert TV joke here)
Re: (Score:3, Funny)
G'night, John-boy.
Their secret: unrevealed (Score:3, Interesting)
Their secret: increasing the light-catching area 'from postage-stamp to traffic-sign dimensions,' reducing the manufacturing time to 1/10th of the competition's
So, what's the secret to their secret?
Environmental impact of cadmium? (Score:5, Insightful)
So how much cadmium is needed, and how much leaks during the manufacturing process? Given that the opposition to nuclear power worries about toxic materials that decay with time, one would imagine there would be some concern about carcinogens that remain a danger forever, and cannot be destroyed.
Re: (Score:3, Informative)
Cadmium is nasty stuff. The primary human exposure to cadmium is cigarette smoke. Not so much from industrial uses such as batteries, pigments etc.
There is some history of cadmium in run off water from mines causing cadmium poisoning in Japan. Cadmium poisoning is known and ouch-ouch disease. It is so painful that people don't die from it, they commit suicide first.
Reliability? (Score:5, Insightful)
Currently you can expect a home solar panel installation to pay for itself within 7 years (here in southern Ontario). If you combine it with wind turbines you can get your money back sooner, and if you spend the extra to be able to sell electricity back to the grid, you can get a payback much sooner because Ontario hydro (the power company here) pays you more than it would charge for the electricity (no distribution fee).
Ideally you want the installation to last for 10 years or more without significant failures, though.
Often "thinner and cheaper" translates to "more easily broken" and "less reliable" - for example, when the units flex in high winds. So my main worry would be about the expected (and achievable) lifetime of the units. Maybe if they gave a five or ten year warranty I'd be OK with it.
Re: (Score:3, Informative)
An off-grid solar + wind system can easily cost $60,000, but if, like us, you live in a rural area it could quite literally be a life saver. Spending $60,000 with no idea how it would affect your costs would be like gambling all your money away on the stock market.
You need to budget for long-term maintenance. And to do that you need to know about reliability of the equipment, and about how long before it's paid for itself, to work out the average costs including replacement parts.
Re:Great big solar cells? (Score:5, Informative)
Parent
Re:Obama's "Manhattan Project" On Alternative Ener (Score:4, Funny)
Parent
Re: (Score:3, Informative)
Lowering our standard of living is out. (Score:3, Insightful)
Oil IS yesterday, and energy savings are good if we can obtain them in a painless way such as insulating our attics or improving the efficiency of our cars. But it's not just the corporations that see no profit in a low-impact life; ordinary people see no pleasure in it either.
I'm tired of installing overpriced compact fluorescents that give dim, ugly light. I'm not going to bring a week's worth of groceries for a family of four home on my bike or on the bus. I'm going to keep my house at the temperature I
Re:Obama's "Manhattan Project" On Alternative Ener (Score:5, Insightful)
Parent
Exxon Valdez (Score:4, Insightful)
I would hold that the Exxon Valdez incident argues FOR drilling ANWR. Just about everything that could go wrong did. But today you could wander that area and never realize anything untoward had ever occurred.
You wouldn't notice anything unless you were a fisherman who had his life destroyed by Exxon Valdez. More than 10 years later [cnn.com] (this from 1999) the fishing industry still hadn't recovered. People in Alaska are still (wrote this February) waiting for compensation [adn.com], 20 years later. So far the fishermen haven't seen a dime from Exxon. Even today studies are finding wildlife is still adversely effected [mongabay.com].
If you think everything is the same for those who had to live through Exxon Valdez you're obviously living in your own fantasy world.
Oil is not a long-term solution.
Agreed. But it IS the only short term solution anyone is proposing.
Drilling for oil off shore is a short term solution? Yea, while people are talking about it, not one of them has said anything about how long it will take before the first drop of oil pumped will end up in someone's gas tank. I surely doubt that will happen one year, forget one month, after exploration starts. The "Wall Street Journal" [wsj.com], which is not an environmentalist group, says offshore drilling "won't affect physical supplies of oil." Here's an iteresting quote from Fadel Gheit, oil and gas analyst with Oppenheimer & Co. Equity Capital Markets Division [cnn.com]: "If we were to drill today, realistically speaking, we should not expect a barrel of oil coming out of this new resource for three years, maybe even five years, so let's not kid ourselves". Oh, and don't blame Democrats for the offshore drilling ban, as president George H.W. Bush [huffingtonpost.com] imposed an executive ban in 1990.
Why waste another dime on trying to extend the supply.
Because we need energy NOW.
Yea, right, if we start drilling now we can pump oil now. HAHA!!! See above quotes.
Falcon
Parent
Re:Obama's "Manhattan Project" On Alternative Ener (Score:5, Insightful)
The reason none of these things have gone on line is because of the attitudes of people like you. There has been no concerted investment, ala the Manhattan Project. In lieu of any concentrated, directed effort to achieve a goal, nothing gets accomplished.
The sun shines reliably for a large fraction of the day--why not invest in that?
I find it curious how your standards of acceptability change: in the case of the alternatives available: switch grass, solar, wind, you play the pessimist. In the case of oil available off the coasts, suddenly you're an optimist. The US Department of Energy [you know, the one with all the Bush appointees in it] has said that 1.) offshore oil will not enter the supply chain for ten years minimum, not "a couple years" [implying 2], as you allege.
Next you toss out the red-herring [meaning irrelevant] point of the Chinese drilling in Cuba--a claim which has been shown to be false so clearly that former GOP Candidate Rudy Guilliani himself uses future tense to describe this alleged problem, which is still a red herring. Do two wrongs make a right? [China allegedly drilling around Cuba and the US drilling off Florida?]
Again, when you address the oil industry, it's all solid to you. When it comes to alternatives, it's "pie-in-the-sky". What are you, an oil-industry flack? You reluctant to learn new things or something?
Though Nuclear does have the benefit of no greenhouse gases, it still has the same fundamental problem that oil does: it's business model is predicated on NOT dealing with its wastes! We STILL doe not have a solution to the incredibly toxic wastes we've been generating for decades. The only solution is to hide the waste. You think this is a viable alternative? Or, are you a Nuclear Energy devotee who has some business interest in that industry. When you advocate dirty technologies, how can we take you seriously?
By the way, I lived in Houston and there is mass transit which I used while working for HP
. And the solution is not--duh--biking 30 miles, it's moving closer to your work and downsizing your stuff.
As I can re-iterate: I have lived all over the United States and this model in NYC is the only one I see as being viable. I've lived and commuted in Omaha, Phoenix, Houston, Cincinnati and Salt Lake City. I always chose to live as close as possible to work.
Such name calling as labeling environmentalism "psychobabble" is convincing fewer and fewer people, my friend. The babble is coming from you fools who seem to prefer fouling your own nests.
Parent
Re: (Score:3, Insightful)
Though Nuclear does have the benefit of no greenhouse gases, it still has the same fundamental problem that oil does: it's business model is predicated on NOT dealing with its wastes! We STILL doe not have a solution to the incredibly toxic wastes we've been generating for decades. The only solution is to hide the waste. You think this is a viable alternative?
Yes.
Solar and wind power cannot provide base energy requirements for the vast majority of the nation. We could continue harvesting power from fission reactors using breeder reactors and refinement for thousands of years with no adverse affect on the environment. The difference between combustion reactions and nuclear is that the waste from nuclear is containable.
Re: (Score:3, Insightful)
The POINT is not the PRESENCE of the oil but, rather, the POLLUTION of the oil. When they find a batch of bad commodity--a freighter of moldy wheat, a herd of steers with Mad-Cow Disease, they don't decide to finish them off. They discard them. To complete the analogy (for those of you who were not paying attention), we recognize that petroleum is poisoning the earth. We need to get off this stuff as fast as possible. I want a president who is NOT beholding to the oil industry, like John McCain is. I want a
Re:Article in two sentances: (Score:5, Informative)
Maybe you should have spent two hours reading the article - you might summarize it correctly then.
The article states that current silicon photocells sell for around $3-$4 per watt.
The new CdS/CdTe cells cost $1.14/W to produce and sell for $2.45/W.
To reach "grid parity" they need to reduce the manufacturing costs to $0.60-$0.75/W and increase efficiency from "over 10 percent" to over 12 percent. The maximum theoretical efficiency for CdTe cells is over 20% and cells with an efficiency of 16.5% have already been made.
Parent
Re:Article in two sentances: (Score:4, Informative)
FTFA:
If you just want to power a billion-dollar space probe, almost any price per watt is acceptable. If you are selling to lonely farmhouses, you just have to charge less than the cost of running a power line to the boondocks. In some parts of the world, competing with grid electricity itself may be an easy game during peak consumption hours. But if you want the off-peak market, you'll have to price your cells at about US $1 per watt. That price is called grid parity, and it's the holy grail of the photovoltaic industry.
Parent
Re: (Score:3, Funny)