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Nanotubes May Improve Solar Energy Harvesting
eldavojohn writes "Scientists are hoping that the 'coaxial cable' style nanotube they developed will resolve energy issues that come with converting sunlight to energy. The plants currently have us beat in this department but research is discovering new ways to eliminate inefficiencies in transferring photons to energy. Traditional methods involve exciting electrons to the point of jumping to a higher state which leaves 'holes.' Unfortunately, these electrons and holes remain in the same regions and therefore tend to recombine. The new nanotubes hope to route these excited electrons off in the same way a coaxial cable allows a return route for electrons. End result is fewer electrons settling back into their holes once they are elevated out of them yielding a higher return in energy."
If you believe these guys:
http://www.trec-uk.org.uk/index.shtml
All we need is to concentrate the power we already have. Apparently, less than 1% of the world's desert would be enough for all the world's power.
I'm not sure whether I believe this, but I certainly think we should be filling those otherwise useless deserts that cover a large portion of the globe with energy harvesting technology. Maybe the Arab countries, fairly replete with this kind of energy rich terrain, could convert from oil economy to exporting something better for the planet?
Peter
The proper headline should be "global warming solved for 3rd time this week".
And I'm sure this is only 5 years away from commercial use, just like every other such announcement.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
This really has the potential for providing a third way (versus semiconductor and photochemical systems) for converting light into electricity (for power or signals). Light is just extremely high frequency radio waves. With conductive nanotubes, one could create dipole antenna arrays for submicron wavelengths.
Two wrongs don't make a right, but three lefts do.
Plus on the economic issue, most nano-things cost kilobucks per square centimeter. Even if the cost came down by a factor of 10,000, it would still be uneconomical at ThunderDome prices.
1) Develop high efficiency, long life solar cells
2) Figure out how to process lunar resources with robotic factories to make said cells
3) Plate the entire far size of the moon
4) Transmit the energy back to earth with a few lunar horizon transmitting stations with atmosphere and cloud penetrating lasers/masers/whatever
5) PROFIT
6) Reserve fossil fuels for high-energy-density required transportation needs, not short distance ground transport or general power production
7) PROFIT plus ENVIRONMENTAL BENEFITS
8) Colonize the moon with the residual infrastructure from the power grid
9) PROFIT plus ENVIRONMENTAL BENEFITS plus OFF-PLANET HUMAN SUSTAINABILITY
10) Use short lunar gravity well to build interplanetary transport, colonize Mars
11) PROFIT plus ENVIRONMENTAL BENEFITS plus FULLY REDUNDANT HUMAN SUSTAINABILITY
12) ???
13) A fully armed and operational battlestation
The link to the situation with plants shows how plants work at the quantum level but just a bit of thought shows that we are more efficient than (rooted) plants at collecting solar power. A small area, say all of the roof tops in the country, can cover all of our electric use and more using 15% efficient silicon solar panels. On the other hand, all of the arable land in the US is not enough to cover our transportation needs through biofuels. Plants may be efficient for their own purposes, but in terms of energy harvesting we do better on our own http://mdsolar.blogspot.com/2007/02/photosynthesis .html. And, as the article points out, we are on the way to doing
even better.s -selling-solar.html
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Sprout Silicon Leaves: http://mdsolar.blogspot.com/2007/01/slashdot-user
The problem is that insolation varies greatly around the world. I would very much love to get solar panels for my house, but up here in Iowa, we get half as much sun as the desert southwest. Yet, we're positively awash in solar energy compared to, say, Washington and Alaska, which have half what we get here.
Halving the amount of energy doesn't just double payback time when you consider cost amortization. It increases it many more times, often making it so that it will never pay back.
Now, up here, self-generated wind power is an economically viable alternative to grid power... *if you don't live in a city*. I've crunched the numbers. Inside city limits, your towers are more expensive (you can't use guyed towers -- not enough space) and your heights are limited too close to the ground. On the other hand, it's perfectly reasonable for farms (and power companies) to invest in. One great thing about the big tower wind turbines is that you lose almost no ground area; you can farm nearly up to their base.
Present day. Present time.
At the 15% efficiency of silicon, quite a lot of roofs have enough area to cover what a building uses. Orientiation comes into this as well as the height of the building. Taller buildings have less roof per unit floor space which tends to track electicity use. At 7% efficiency, the number of roofs that can cover 100% of the building's use goes down a lot because we're at the edge of feasability at 15%. So, cheaper, lower efficiency solar panels, can turn out to work better where surface area is not at a cost premium. This tends to be in rural areas rather than where most houses are.
s -selling-solar.html
Commercial buildings can often benefit from lower cost, low efficiency panels because they are gaining from using space that they otherwise would not and they are more bottom line driven and can't cover they're full electic use under either senario.
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Go Solar for what you already pay anyway: http://mdsolar.blogspot.com/2007/01/slashdot-user
Definitely not a jump start! That takes the highest current draw of all. These things are good if you leave a vehicle parked for a long time. They keep the battery topped off.