Solar Concentrator Cells Ready to Make a Comeback? IBM Unveils "Breakthrough"

[garybeck]

When I first went to school to learn about solar energy 20 years ago, we learned about concentrator cells. This is when mirrors (or fresnel lenses) are used with solar panels to increase the intensity of the sunlight that hits the solar cell. <snip> excess heat caused the cell to actually decrease its output, and it eventually damaged the cell.



Now 20 years later, it appears solar concentrators are making a comeback. IBM has developed a way to deal with the heat problem and keep the cells cool. This could be yet another (of many) recent new technologies that will make solar energy not only more affordable but even competitive with "conventional" energy sources.

more: http://solarbus.org/blog/?p=14

[Warpy]

1. All they need to do is develop a solar cell that doesn't burn up

or out at 400 degrees F. That's what my very primitive solar oven does in midsummer.

(You didn't think I'd heat up the house in July in the desert to bake my bread, did you?)

[garybeck]

3. 400 is very good for a home made solar oven!

I have a commercially made solar oven that gets up to 350, but not often higher. then again I'm in Vermont and you're in the desert !

[Warpy]

17. Mine is commercially made

My homemade solar dye setup would boil water, but I never checked to see how hot it actually got. I did manage to dye yarn in a simple plastic jug set in the sun here, but the water would never boil. It did get too hot to touch.

When the jerrybuilt oven disintegrated, I splurged some of my inheritance on a Sun Oven.

[garybeck]

19. mine is a Sun Oven too.

i love it. I've actually burned food (and my hand) on it before.

[Warpy]

21. I've learned to wear a mitt or even a leather glove

when I open that door to remove whatever I'm cooking.

I love mine. I just wish it did better in wind.

[garybeck]

22. yeah, me too

i love it when I open the door and a huge cloud of steam escapes. it's very impressive when i'm at a show. we always bake solar cookies and give them away. it's in the Solar Bus Movie which you can watch here:

http://solarbus.org/photos/movies/solarbusmovie.shtml

[Greyskye]

2. Impressive.

For instance, by moving from a 200 sun system ("one sun" is a measurement equal to the solar power incident at noon on a clear summer day), where about 20 watts per square centimeter of power is concentrated onto the cell, to the IBM Lab results of a 2300 sun system, where approximately 230 watts per square centimeter are concentrated onto the cell system, the IBM system cuts the number of photovoltaic cells and other components by a factor of 10.

(...)

The trick lies in IBM’s ability to cool the tiny solar cell. Concentrating the equivalent of 2000 suns on such a small area generates enough heat to melt stainless steel, something the researchers experienced first hand in their experiments. But by borrowing innovations from its own R&D in cooling computer chips, the team was able to cool the solar cell from greater than 1600 degrees Celsius to just 85 degrees Celsius.

[garybeck]

4. yes, it's amazing what they can accomplish when they try

for too long, technology has been focused on making better Nintendo games, faster computers, and useless gadgets that people don't really need.

if they took just a fraction of the R&D they spend on all that stuff and worked on renewable energy, we wouldn't even be talking about coal or nuclear, other than in the history books.

[phantom power]

5. I don't see the percentage in doing this, when we can do straight thermal solar.

With CPV, the extreme heat is a major engineering problem, instead of just an asset. And the conversion efficiency is comparable.

[garybeck]

8. one thing to consider

solar thermal (at least on the large scale) is only practical in the southwest desert, like the new eSolar system touted by Google folks.

PV works anywhere. You'll never see an eSolar plant in Vermont. But you could see PV concentrators here when they hit the market. So I see practical uses for both.

[phantom power]

10. I find that hard to believe.

If you have the photons, you have the photons. Regardless of how you use them to pump electrons.

[garybeck]

18. Not true

There is a threshold for solar thermal to work. You need full sun to get the fluids hot enough, at least on a large scale. With PV, the output is directly proportional to the intensity of the sunlight. There are PV applications in place all over the Northeast where days are shorter, there and there are less hours of peak sun per day. On the other hand, you will never see an eSolar power plant in Vermont.

[phantom power]

27. I see the point about minimum fluid temp, however...

you can still play the game. For instance, suppose you have a thermal plant that wants heat-exchanging fluid at 500C. Your fluid generates steam for two turbines. On days where the sunlight is at 50% optimal intensity, you can idle one turbine, run the heat-exchanging fluid at 50% slower through the collectors, and get your 500C for one turbine. No doubt that's oversimplified, but the principle applies.

[electropop]

12. According to the story, cost and efficiency of thermal are not as good.

I actually think the best is a combination: Take the "waste" heat from the concentrator and make use of it for domestic hot water, industrial heating, or even thermoelectric generation to squeeze out a bit more electricity.

[NNadir]

6. Wow. Another "breakthrough!"

It is amazing that after 514,299 breakthroughs announced on this website, the number of exajoules produced by solar eleectricity is still not one.

[garybeck]

7. yes, that's because there is not an even playing field

if you took away the subsidies we fork out to oil and coal, and account for increased scale of production even with today's solar technology, solar energy would be competitive. It's all politics.

The argument that you continually make here in this forum is a joke. "Solar has never produced one exajoule..." blah blah blah.

I suppose you were telling the astronauts back in the 60s that they can never make it to the moon, just because NO ONE HAS EVER DONE IT BEFORE?

And I suppose that radios really shouldn't exist because 100 years ago they didn't exist?

The fact that solar and renewables has only produced a small amount of power thus far is absolutely 100% and completely IRRELEVANT and with all due respect you make yourself look rather foolish when you keep saying it. Try to come up with something that actually makes sense when you are being skeptical of renewable energy.

In n reality, the fact that solar and renewables have not produced significant power thus far is what makes this whole discussion promising and exciting. It's good to know that there is emerging technology that can get us out of this mess. Now if we can just change the politics so that our leaders make the right decisions to help make it happen...

Solar energy isn't feasible? That's not what Scientific American says:
http://www.sciam.com/article.cfm?id=a-solar-grand-plan&page=1

[NickB79]

9. As others have pointed out here, solar panel research is semi-conductor research

And the US has invested many BILLIONS of dollars into semi-conductor research over the past few decades. Other nations have been researching solar with massive amounts of government funding for decades as well (Japan, Germany, etc). Despite this, solar power on a global scale is still a tiny fraction of that generated by fossil fuels, unfortunately.

The cry of insufficient funding for solar research rings hollow.

[garybeck]

15. Not exactly

research is funded with specific goals. semiconductor research is a broad topic with many differnet goals.

engineers trying to make smaller or faster computer chips are not doing the same kind of research as renewable energy R&D.

nonetheless, it doesn't matter. even without sufficient funding, the price of fossil fuels is skyrocketing and the price of renewables is going down. the government may be the last one to wake up. Companies like NanoSolar, eSolar, along with the increased demand for clean technologies will make it happen even without proper government funding.

[NNadir]

11. Bullshit.

Solar electricity is one of the most subsidized forms of energy in the world.

Your evocation of radios is entirely specious. Radio did not require 50 years of subsidy and hype to become a reality.

When, in your imagination, was the solar cell invented?

Try 1954.

It will be a great day when the "solar will save us" crowd announces its first exajoule. Until then, it's all just denial and hype.

[garybeck]

14. Bullshit back at you.

"Solar electricity is one of the most subsidized forms of energy in the world."
Bullshit:

Government directly subsidizes oil consumption through preferential treatment in tax codes. A multitude of federal corporate income tax credits and deductions results in an effective income tax rate of 11% for the oil industry, compared to the non-oil industry average of 18%. If the oil industry paid the industrywide average tax rate (including oil) of 17%, they would have paid an additional $2.0 billion in 1991.
http://www.ucsusa.org/clean_vehicles/fuel_economy/subsidizing-big-oil.html

Europeans spend about $10 billion or so (USD equivalent) annually to subsidize fossil fuels. By contrast, it thinks the American oil and gas industry might receive anywhere between $15 billion and $35 billion a year in subsidies from taxpayers.
http://media.cleantech.com/node/554

Instead of requiring energy companies to stand on their own feet, the government has set up a perpetual subsidy system. Large energy companies act as if they cannot survive without taxpayer handouts, perpetuating an endless cycle of subsidies. The government should stop giving taxpayers' dollars to powerful energy companies.
http://www.taxpayer.net/energy/oil-gas.htm

Now consider Bush's 2009 Budget proposal:

$222.7 million increase in fossil energy funding, which amounts to a 25 percent increase over FY 08 appropriations.

$385.5 million increase in nuclear energy funding, which amounts to 37 percent increase from FY 08 appropriations.

$0: Proposed budget for the Renewable Energy Production Incentive program, which provides financial incentive payments for electricity produced and sold by new qualifying renewable energy generation facilities. This is a 100 percent cut from the $5.0 million allocated in fiscal year 2008.

$12.3 million: Proposed cut to the solar energy program, which works to accelerate the development of solar technologies as energy sources for the nation and the world, as well as educate the public about the value of solar power as an energy choice. This is a 7 percent cut from the fiscal year 2008 appropriations level.

[Wilms]

16. Let's try adding to that the ALL costs involved with Middle East oil.

We probably can't.

Suffice to say protecting the flow of oil helps create the worlds largest consumer of oil...the US military.

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=389x3377267

[garybeck]

20. Sooooooo true!

When we finally have a solar economy, you won't see Bush III starting a war in Argentina over who can use the Sun! No more of our country's young men and women will have to die for oil. Thanks for adding your correct perspective!

[Dead_Parrot]

25. But then there's this:

Solar may receive less funding than fossil and nuclear - but it gets more than geothermal, wind, hydro and biomass combined:



And it produces less power than any of them.

[jpak]

24. Horseshit - commercial (mass) production of PV modules began 1976 - not 1954

Reagan and the solar hatin' GOP cut solar R&D and ended federal homeowner solar tax credits in 1983.

New Jersey's solar rebate program began in 2002 - not 1954

Democrats reinstated federal homeowner tax credits in 2006 - not 1954

California's solar initiative began in 2007 - not 1954.

If solar had received the $77 billion that nuclear received since 1954, we would have brazillions of solar ex-o-jewels by now.

[electropop]

13. "Alternative energy is small-scale" so let's not let it grow.

Circular logic. I wish they would teach logic and critical thinking in school, as they did when I was a kid.

[jpak]

26. Global renewable power capacity is >240 GW and produces exajoules of electricity each year

http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=115&topic_id=137124

tthe iignorance oof ssolar hhaters iis aappalling...

:evilgrin:

[JohnWxy]

23. You might find this interesting: Start-up: Affordable solar power possible in a year - USA Today

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x145507