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| Solar Cells could reach 60%+ efficiency w nanotech treatment |
| 2005-05-25 |
| Its been a while since we had much on this subject. While this is just a lab report, its nice to know because the unused roof acreage in the US is so vast that if we could really get 60% efficiency in cells, it would change the whole ball game Quantum Dot Materials Can Reduce Heat, Boost Electrical Output Monday, May 23, 2005 Golden, Colo. — Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have shown that nanotechnology may greatly increase the amount of electricity produced by solar cells. ...an NREL team found that tiny "nanocrystals," also known as "quantum dots," produce as many as three electrons from one high energy photon of sunlight. When today's photovoltaic solar cells absorb a photon of sunlight, the energy gets converted to at most one electron, and the rest is lost as heat...." ..solar cells based on quantum dots theoretically could convert more than 65 percent of the sun's energy into electricity...The best cells today convert about 33 percent of the sun's energy into electricity... |
| Posted by:mhw |
| #14 the saudi princes just felt a chill go down their spines |
| Posted by: 2b 2005-05-25 20:06 |
| #13 It may well be the practice to speak of solar cells as being x% efficient but I find the headline highly misleading. Sunshine is free and unlimited and therefore the amount of input is irrelevant to the solar cells viability. What matters is economic viability which is also a rough proxy for total aggregate cost of the energy inputs. |
| Posted by: phil_b 2005-05-25 20:03 |
| #12 Three electrons per photon is impressive: I did a class paper with an Army ROTC candidate in Grad school that used a fuel cell powered by sun-excitated nitrosyl (a mix of nitric and sulfuric acid), which produces two electrons per photon. Covering an average roof in Tucson with the required solar panels would more than power the house with enough to spare for sale. Drawback: nitrosyl turns into aqua regia when exposed to water, so we had to concede the possiblity of a REAL china syndrome occurring if a baseball broke the glass. I can't remember the acreage required to power Tucson Arizona if we opted for a base-ball free solar power farm, but it wasn't much at all, IIRC. That's at *2* electrons per photon. *3* is jaw-dropping. |
| Posted by: Ptah 2005-05-25 19:32 |
| #11 We could defend them with electro-magnetic railguns shooting wasteful 1972 Buicks. |
| Posted by: Shipman 2005-05-25 16:01 |
| #10 It'd be nice if the barges had electrolysis equipment on them, too. |
| Posted by: 11A5S 2005-05-25 15:26 |
| #9 Gut supertankers and convert them into bulk liquid hydrogen carriers. They can circle around in the tropics towing barges full of solar cells. When they're full, hand off the barges to another tanker, return to port and offload the hydrogen. Even though it might take years to put in the infrastructure for cars to use H2, one could convert gas turbines quickly to use hydrogen. In many cases, the gas turbines are on barges at the ports for surge power production. |
| Posted by: 11A5S 2005-05-25 15:14 |
| #8 Use the solar to produce the hydrogen cells. |
| Posted by: Fred 2005-05-25 14:50 |
| #7 That's great, but I don't think it solves the basic problem with solar: you need sunlight for it to work. What happens when you've got 4 cloudy days in a row? (not unheard of in the northern & eastern US) I'm not knocking it - I'm just wondering. I can see where solar would be great in the Southwest, but here in Virginia? Or in New York? |
| Posted by: Barbara Skolaut 2005-05-25 14:49 |
| #6 yet, wouldn't a key determining factor be the cost of production? I understand it's still in the laboratory, but since there are no nanotech products on the market yet, I assume producing nano-anything would be fairly cost prohibitive. So making these things in quantity might add too much to the net cost of electricity. |
| Posted by: PlanetDan 2005-05-25 14:28 |
| #5 agreed that efficiency is only one number but its an important number all things being equal, doubling the efficiency reduces the cost/peak by 50% but even better, since the nanodoping allows a bigger part of the spectrum to be used, the gain in cost/watthour is reduced by more than 50% |
| Posted by: mhw 2005-05-25 12:54 |
| #4 Whoops.... meant $/(peak watt) |
| Posted by: Damn_Proud_American 2005-05-25 12:29 |
| #3 Efficiency of the cells doesn't mean anything when looked at by itself (except in rare circumstances). The number to look at is %/(peak watt). The least "efficient" solar cells (made by konarka) are the most cost effective... about $3/watt. |
| Posted by: Damn_Proud_American 2005-05-25 12:27 |
| #2 Sweet! If they could get that kind of efficiancy, solar could be affordible. Right now IIRC, installing solar takes up to 20 years to pay itself off in energy savings. Knock that down to 5 years and I'll have it installed. |
| Posted by: mmurray821 2005-05-25 12:14 |
| #1 Pretty exciting for me; I spend a good portion of my time living in a place that runs (partially) off of solar. Thanks mhw! |
| Posted by: Secret Master 2005-05-25 11:57 |