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Iron pyrite is the top material picked by a University of California at Berkley and Lawrence Berkeley National Laboratory to replace silicon in solar cells. While modestly less efficient than crystalline silicon, its dramatic cheaper in processing costs and very abundant. Adopting it as a replacement to silicon or thin films could dramatically cut costs and enable enough production to supply the world's power needs, according to the team.  (Source: Crystals Guide)
Search for more abundant, lower cost materials should help improve solar cost efficiency

Solar power is an incredibly promising alternative energy technology.  However, the problem with converting solar energy directly to solar power via photovoltaics or other designs is that the cost of producing power is simply not cost competitive with nature's designs -- coal or petrol.

The cost issues are not for lack of efficiency.  Scientists have milked very high efficiency out of the cells, iteratively raising the yield year by year.  However, the high cost of silicon, the primary material for solar panel cells, keeps the costs high even as efficiencies experience dramatic gains.

In order to make solar cost competitive, researchers at University of California, Berkeley, and the Lawrence Berkeley National Laboratory (LBNL) are spearheading the search for a silicon replacement for the solar industry. 

The team surveyed 23 promising semiconducting materials and then pared the field down to the 12 that are abundant enough to meet or exceed the world's yearly energy needs.  From there 9 were selected, which exhibited significant cost savings in raw material costs over crystalline silicon.

Daniel Kammen, UC Berkeley professor of energy and resources, and colleagues Cyrus Wadia of LBNL and A. Paul Alivisatos of UC Berkeley's Department of Chemistry discovered that some superior solar choices may have been overlooked due to the desire to keep the status-quo of silicon.  They believe before solar power can be deployed on a broad scale, the basic science must be reevaluated to ensure that the industry is using the best possible materials, rather than blindly proceeding. 

Wadia states, "The reason we started looking at new materials is because people often assume solar will be the dominant energy source of the future.  Because the sun is the Earth's most reliable and plentiful resource, solar definitely has that potential, but current solar technology may not get us there in a timeframe that is meaningful, if at all. It's important to be optimistic, but when considering the practicalities of a solar-dominated energy system, we must turn our attention back to basic science research if we are to solve the problem."

Today's top solar materials are crystalline silicon and thin film CdTe (cadmium telluride) and CIGS (copper indium gallium selenide).  Silicon is abundant, but costs a great deal to process.  The exotic metals like indium used in thin films are cheaper to process, but less abundant.  If the world switched to all solar, they would quickly run out.  States Professor Kammen, "We believe in a portfolio of technologies and therefore continue to support the commercial development of all photovoltaic technologies.  Yet, what we've found is that some leading thin films may be difficult to scale as high as global electricity consumption."

Wadia adds, "It's not to say that these materials won't play a significant role.  But rather, if our objective is to supply the majority of electricity in this way, we must quickly consider alternative materials that are Earth-abundant, non-toxic and cheap. These are the materials that can get us to our goals more rapidly."

The team's top candidates for a replacement material are iron pyrite, copper sulfide, and copper oxide.  Of them, iron pyrite is the cheapest, being plentiful and easy to process.  While nanoscale science has shown that cells of such unconventional materials will experience modest efficiency losses, the researchers say that these costs will be easy offset by the decrease in raw materials and processing costs.

Professor Kammen concludes, "As the U.S. envisions a clean energy future consistent with the vision outlined by President Obama, it is exciting that the range of promising solar cell materials is expanding, ideally just as a national renewable energy strategy takes shape."

The team's research was funded by the U.S. Environmental Protection Agency, the Energy Foundation, the Karsten Family Foundation Endowment of the Renewable and Appropriate Energy Laboratory.  It appears in the journal Environmental Science & Technology.



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RE: How modest is modest?
By bhieb on 2/20/2009 12:44:05 PM , Rating: 5
quote:
... to my fellow environmentalists...wasteland, like deserts.


Just poking fun but I love that you call yourself an environmentalist and use the word wasteland :) No land is a wasteland for a true tree hugger. They would point out that installing large square feet of artificial shade in a dessert dramatically changes the ecosystem. Since shade is a valuable resource to most dessert dwellers, and adding more will cause some to thrive artificially.


RE: How modest is modest?
By JasonMick (blog) on 2/20/2009 1:27:51 PM , Rating: 5
There's environmentalists and then there's practical environmentalists.

A desert solar array would not have a crippling effect on most of the desert organisms, as it would have little effect on the sediment, temperature, or vegetation level (or lack thereof). Further, the desert is an ecosystem of limited biodiversity. It makes far more sense to utilize this space while protecting ecosystems like deciduous forests and swamplands, and rainforests. If you want to be practical, focus on protecting the regions with the highest species density -- aside from conservation for the sake of preserve biological diversity and world balance, this also has economic benefits as the millions of creatures there are more likely to contain valuable medical chemicals than the handful of desert creatures. Blind idealism gets good ideas nowhere, its practical idealism that makes a real difference.

I'm by no means advocating scrapping protection efforts for desert creatures, just saying that its an area of lesser biodiversity, something anyone familiar with basic biology knows. There's not many tree's to hug in the desert -- maybe some cacti, but not many trees.
(I make noted exception to areas of dense desert vegetation, such as the Joshua Tree Nation Park)


RE: How modest is modest?
By bhieb on 2/20/2009 1:53:07 PM , Rating: 2
quote:
Blind idealism gets good ideas nowhere, its practical idealism that makes a real difference.


Agreed, and as stated just poking fun. Some things have to be compromised on, and the desert is a good place to put these.

Regardless of ones beliefs (Darwin/Intel Design), mankind is the dominate species, and by either definition we can/should use any and all of the planets resources as we see fit. Either because we are "evlovled" to a level that we can do as we see fit until nature corrects the imbalance (a nice ice age or severe global warming would do). Or because we are "allowed" by a higher power to do so until he/she/it smites us for doing it poorly. In either case we can do what we want so we should if it meets our needs. The planet is an inanimate object that will continue to float around in space with or without us. So self preservation is our only real concern, the debate is what is best for us?


RE: How modest is modest?
By bhieb on 2/20/2009 1:57:27 PM , Rating: 2
Wow just re-read that WAY to philosophical for a Friday and really off topic. You can ignore that babble.


RE: How modest is modest?
By Spuke on 2/20/2009 3:49:36 PM , Rating: 1
It's fine with me.


RE: How modest is modest?
By Adul on 2/20/2009 4:54:21 PM , Rating: 2
ever been to the desert southwest?Its not really lacking vegetation here. There is a good amount of plant life, and various desert critters.


RE: How modest is modest?
By Oregonian2 on 2/20/2009 6:44:32 PM , Rating: 2
Yes, the only politically acceptable places for massive solar panels are locations that are already "ruined". Big cities and/or perhaps existing farms (run up the price of corn for additional reasons).


RE: How modest is modest?
By ekv on 2/20/2009 10:55:12 PM , Rating: 2
I wish there were more "practical environmentalists". There are 3 Solar plants scheduled for "remote" areas in a certain west coast state. A couple hundred miles above Joshua Tree National Park in fact. The solar power plants would create many private industry jobs and actually put a bit of power onto the grid.

The latest I've heard however is that there are 2, not 1, but 2 lawsuits by environmentalists to stop the solar power plants. Insanity.


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