Technology Review has an article on thin-film solar, mostly focusing on First Solar. This stuff is very, very close to competitive with conventional solar panels and on a clear path to being competitive with traditional fossil-based electricity sources. It's an exciting time.
Speaking of solar excitement: A team at the Univ. of Delaware has just broken the previous world record for solar cell efficiency. The previous record was 40.7% efficiency, held by the Defense Advanced Research Projects Agency (DARPA). The UD team hit 42.8%. They're shooting for 50%.
Skeptics point out that solar power has been "on the verge of a revolution" for about 30 years now, so I realize I risk mockery when I say this, but nonetheless, this time it really does seem true that ... solar power is on the verge of a revolution.
Check back in five years. If I was wrong, mock away.
‘Heretic’ battles straw man
Comments
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JMG Posted 4:59 pm
01 Aug 2007
I don't know exactly what the efficiency of a solar panel is -- presumably it means the efficiency of solar to electric conversion, averaged over some period, at some reference temperature and % cloud cover (eff = energy out/energy in, generally).
What I'm really interested in, and what might be a more practical number, is the energy payback period under the same conditions: how long before the panels produce begin producing net energy, and how long will they hold that efficiency.
Save the world: Reduce greenhouse gas emissions 5% annually.
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David Roberts Posted 5:35 pm
01 Aug 2007
Lots and lots of work is involved getting efficiency up in real world conditions with mass manufactured panels. I don't think thin films have cracked the high teens yet, and those type of numbers cost you a buttload.
Yeah, so obviously, in practice what you care about is kwh/m2. That number keeps getting better and better for thin films, pretty rapidly.
grist.org
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kenrosso Posted 11:47 pm
01 Aug 2007
Its important for readers to know that they don't have to wait for solar to undergo the "revolution" in order to get it on their roof today.
And, overall, we need leaders, not tech watchers, to stop global warming.
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Biodiversivist Posted 1:37 am
02 Aug 2007
http://www.findsolar.com/index.php?page=rightforme
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
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sunflower Posted 1:46 am
02 Aug 2007
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rmcleod Posted 3:06 am
02 Aug 2007
http://entropyproduction.blogspot.com/2006/05/solar-payba ...
Efficiency standards are usually under the Air-Mass 1.0 standard, which is basically 1000 W/m^2 at 25 ^C:
http://entropyproduction.blogspot.com/2005/08/air-mass-15 ...
Most systems that achieve super-high efficiency are tiny (less electrical losses) and use concentrating optics (which do not work so well in the presence of clouds). As such, they are laboratory results.
--
entropyproduction.blogspot.com
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sunflower Posted 3:23 am
02 Aug 2007
Solar concentrators produce zero watts in clouds, but if they could (plus blue sky indirect) then the system performance would increase 15%.
Annual direct normal insolation:
http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/ ...
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sunflower Posted 3:50 am
02 Aug 2007
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Biodiversivist Posted 4:26 am
02 Aug 2007
But, is it a model that can be scaled up and put in urban settings? It still relies on grid electricity for hot water, lighting etc. It is also rural, requiring more transport energy. The low cost is probably attributable to your own labor and design inputs and is probably modest in size. We can't burn wood for heat. The cost of that house if someone were to pay an architect and a general contractor today would be a whole lot more than what you did it for.
The trailer I lived in for four years cost $4,000. Sold it when I was done for same. Propane used to heat it for a year, $400. Monthly electric bill, $40. Riding bike to work two miles away, $0.
My point? You don't need radical new technology to reduce energy use. But, you would need to make compromises. People don't want to live in 300 square foot trailers in trailer parks. People don't want to use a clothes line or maintain a wood stove. They like their dishwashers, air conditioners, gas furnaces etc. In the background of all of these discussions lies the fact that most of us live in homes that are much larger than we need. Small homes, when well designed can be even more comfortable.
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
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sunflower Posted 5:15 am
02 Aug 2007
I've got 2 chords by the door to split for all winter's heat. That's just 3 or 4 trees, the easily accessible ones that fell last November's storm. One acre would be sustainable heat - forever. The concrete passive solar house is 3500 square feet, has double duty as lab and shop. It looks like any home, just with embedded energy efficiency. I expanded on what Amory Lovins did in his home.
It's not what I did, but how. That was the experiment, the lowest possible cost. Spending money has overhead, more money - commuting for income, income tax, loan interest, tax and medical for hired workers, expedient new materials, more overhead for overhead... Self reliance and voluntary simplicity can save much time and money yielding uncompromising independence and good health.
Urban settings could use pellet stoves without leadership or district heating with leadership.
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Biodiversivist Posted 5:55 am
02 Aug 2007
In the end, it all comes down to biodiversity. Poison Darts--Protecting the biodiversity of our world
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GreyFlcn Posted 6:20 am
02 Aug 2007
Cept that was solar thermal :P
http://www.luz2.com/apage/12219.php
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sunflower Posted 7:47 am
02 Aug 2007
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Gar Lipow Posted 12:14 pm
02 Aug 2007
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sunflower Posted 3:18 pm
02 Aug 2007
Some thin films have substrate issues. Plastic substrates will not amortize. Solar thermal power conversion systems have expensive metal materials issues from heat cycling. Small heat engines will not amortize. High-intensity pv have thinly understood cooling costs. Cogenerating power and heat is most difficult to price because of so many variables. Most of the solar concentrator research was terminated so much of that data is quite old.
To further complicate comparisons, the power cost numbers assume mass production, which does not exist yet. Depending on who you talk to, high-intensity pv could be anywhere from $0.05/W to $1.00/W plus concentrator. The best numbers I know of are from Spectrolab at $10/cm2, 37% efficient, with up to 100 W/cm2 flux or $0.27/W. I believe $0.50/W(e) system is achievable.
Another excellent dimension is to displace natural gas used for low and mid temperature process heat so that the natural gas saved can be used for high temperature baseload power with combined cycle turbines. Collectively, we should be able to do $0.20/W(t). Return on investment and rapid scale up is best with low-cost simple solar systems and mature power generating systems.
Also, there are a lot of former dot.com kids doing solar power things that will not pencil out, but they are none-the-less sucking up tens of millions of dollars from investors in Silicon Valley and elsewhere. Bubbly.
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