Solar Energy: Charged For The Future

Science Daily ^ | September 12, 2006 | American Chemical Society

[Brilliant]

Once regarded as costly and impractical, solar technology is now poised to play a larger role in the future, thanks to new developments that could result in lower costs and improved efficiency. Potential applications include cell phones, computers, automobiles, homes and office buildings.

The American Chemical Society will address the progress and challenge of this technology during a first of its kind symposium, "Science and Technology of Next Generation Photovoltaics," from Sunday, Sept. 10, through Tuesday, Sept. 12, in San Francisco during the Society's 232nd national meeting.

Here are a few highlights of research toward improving the efficiency of solar cells:

"Plastic" solar cells show gains in performance -- Nobel Prize winner Alan J. Heeger, Ph.D., and colleagues at the University of California, Santa Barbara, say that new developments in "plastic" solar cells, particularly chemical modifications to titanium oxide layers, could provide efficiencies of up to 15 percent in the future. He already has developed plastic solar cells with efficiencies between 5 percent and 6 percent, considered among the highest to date for this type of solar cell. These developments could pave the way for wider use of plastic solar cells, a type of conducting polymer, which are increasingly seen as a low cost, efficient and long-lasting source of solar energy. Heeger, a professor at the University, shared the 2000 Nobel Prize in Chemistry for his contributions toward the discovery of plastics that conduct electricity. His presentation will be delivered by study co-author and University colleague Kwanghee Lee, Ph.D.

Ultrathin, dye-sensitized solar cells called most efficient to date -- Researchers in Switzerland have developed dye-sensitized solar cells that have reached the highest efficiencies to date among a new generation of thin film photovoltaic devices that show promise as a low-cost energy source. The new cells, composed of an ultrathin film of nano-sized semiconductor crystals such as titanium dioxide, have been shown in laboratory studies to produce efficiencies of 11 percent, whereas most new solar cells have efficiencies between 4 percent and 5 percent, according to Michael Graetzel, Ph.D., a chemist at the Swiss Federal Institute of Technology, Lausanne. These cells, which can be engineered into inexpensive, flexible sheets, could be used as coatings on glass windows to supply electric power to homes and businesses or as coatings on tents to supply power for soldiers in the field. The cells could be used in consumer applications within two to three years, the researcher says.

Carbon nanotubes could boost efficiency of solar cells -- Researchers at the University of Notre Dame in Indiana say they have found a new and promising way to boost the efficiency of solar cells. In preliminary studies, carbon nanotubes that were engineered into the architecture of semiconductor solar cells (composed of cadmium sulfide, zinc oxide and titanium dioxide) resulted in a doubling of the cells' photoconversion efficiencies (converting light into energy). In some cases, the efficiency of solar cells jumped from 5 percent to 10 percent in the presence of carbon nanotubes, according to Prashant Kamat, Ph.D., a professor of chemistry at the University. Carbon nanotubes also could be added to other types of solar cells, such as dye-sensitized solar cells and organic solar cells based on conducting polymers, to create similar or even stronger efficiency boosts, he says.

The American Chemical Society -- the world's largest scientific society -- is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

[HEY4QDEMS]

Percent of what??????????

[Mo1]

.

[RKV]

It appears that my alma mater is making up for producing Joe Wilson and Barbara Bodine. Go Gauchos!

[JustDoItAlways]

The solar community needs to come up with something that actually works for once or they should get off the pot.

[Lee N. Field]

Raw solar power is roughly 1kw/square meter, IIRC. What percentage of that 1kw/sqmeter is turned into electricity?

[DManA]

If it's so promising why all the weasel words?

is now poised...could...could...in the future..These developments could pave..been shown in laboratory...could be used..could be ...

[DBrow]

I won't buy into solar because of "efficiency". It's dollars per watt installed, that is the only practical consideration. Efficiency means how many square meters of panel, that's all (life cycle being the same).

If one system costs $13,000 installed and another costs $36,000 but is more "efficient", which should I buy?

Here are links to solar power calculators that allow you to figure out how much solar costs to install. Note that most of the "return of investment" numbers involve the Marxist concept of forcing your utility to buy your extra solar capacity at a rate much higher than the wholesale power buys they usually do (and your neighbors pay the difference with their utility bills and taxes).

http://www.bigfrogmountain.com/calculators.cfm

http://www.clean-power.com/Kyocerasolar/default.asp

http://www.findsolar.com/proestimator/?contractorid=1690

[P-40]

I think converting sunlight into mechanical energy is still a better deal than trying to convert it to electricity. Here are some links to various ways of doing that.

http://www.cleantechblog.com/2006/03/news-on-rise-of-solar-concentrator.html

[Uncledave]

Renewable Energy Ping

Please Freep Mail me if you'd like on/off

[Salgak]

Percent of energy falling on them (i.e. light) actually converted to electricity, I would guess. That's the usual measure of efficiency. .

[taxed2death]

This is a link from the page you provided.
http://thefraserdomain.typepad.com/energy/2006/02/u_wisconsin_stu.html

I don't know a lot about this stuff, but this would certainly seem like it would work for power generation in the southwest USA.

Concentrate the suns energy onto a surface....heat water hot enough to make steam and then send it to a steam generator plant.

Seems simple although I do not know how efficient it would be.

[P-40]

I don't know a lot about this stuff, but this would certainly seem like it would work for power generation in the southwest USA.

I suspect it would work well in some parts of Texas where there is plenty of intense sun. Water would be a bit of a problem but not that big of one.

[Realism]

forcing your utility to buy your extra solar capacity at a rate much higher than the wholesale

Here in N.Y. the utilities buy nothing, you are allowed to use the grid as a means of storage. The utilities sell it at peak rates during the day while most residential solar homes draw it back during non-peak hours. Who's making out better here?

[MrEdd]

Note that most of the "return of investment" numbers involve the Marxist concept of forcing your utility to buy your extra solar capacity at a rate much higher than the wholesale power buys they usually do (and your neighbors pay the difference with their utility bills and taxes).

Extremely poor analysis on your part, DBrow. The application of marxism occurs much earlier when imminent domain is used to force property owners to accept permanent easements across their property. Buying extra solar capacity at consumer rates inadequately compensates for that infringement.

[Einigkeit_Recht_Freiheit]

Solar will probably only ever be good for:
1). Heating water
and
2). Powering high-efficiency mobile devices.

In the first circumstance, you already get pretty competitive prices because you waste so much less energy.

In the second circumstance, the US DoD has a vested interest because the number of toys its soldiers are carrying already weighs 80lbs and is only going to get heavier if they don't figure out a way to get more efficient and recharge them.

A soldier in the remote field of the Hindu Kush would be much happier if his high-tech gear could be charged by the role-up light-weight solar panel he had rather than the giant lithium battery.

Barring some unimaginable technolgical breakthrough solar will never provide large amounts of electricity. Wind is a better alternative and really just converted solar energy anyway. The same is true of biomass. And, for that matter, fossil fuels.

[DBrow]

LOL I think you're right!

[DBrow]

http://www.freerepublic.com/focus/f-news/1646407/posts

This thread discusses the economics of solar subsidies.

[DBrow]

There is a prototype solar power plant that does this at Sandia Albuquerque.

There was a solar commercial plant in Bagdad, CA that couldn't make a profit and went bankrupt.

Both use a field of steerable mirrors that focus on a boiler. The Sandia one uses molten KCl as a heat transfer medium, I don't know about the California one.

An OK technology but nobody has made it work yet.

[Drammach]

Concentrate the suns energy onto a surface....heat water hot enough to make steam and then send it to a steam generator plant.

I saw a solar power project at the University of North Dakota during the 70's that used solar collectors to heat water..
Basically, the collectors were just large aluminum panels with channels molded into them, to hold water..
The water was heated, and run through some sort of heat exchange system, which actually powered all the lights and air conditioning, electrical power for a 60ft trailer..

The system did not want steam...
When the temp got too high, and steam was generated, it was bled off..
Much like refrigerants in an air-conditioning system, or an ice machine, you don't want "bubbles" of air, gas, steam, etc. in the system..
It reduces the pressure and forces the compressors to work harder for the same effect..

So, Solar would have an either-or effect..
You heat water, or create steam, but not both..
At least within a single system..