Caltech Makes Flexible, 86% Efficient Solar Arrays

strredwolf writes "Caltech has released a flexible solar array that converts 95% of single-wavelength incandescent light and 86% of all sunlight into electricity. Instead of being flat-panel, they stand thin silicon wires in a plastic substrate that scatters the light onto them. The total composition is 98% plastic, 2% wire — the amount of silicon used is 1/50th that of ordinary panels. So as soon as they can get these to market, solar could be very viable and cheap to produce." Update: 03/01 21:02 GMT by KD : Reader axelrosen points out evidence that the 80%+ efficiency figure is wrong. MIT's Tech Review, in covering the Caltech announcement, says that the new panel's efficiency is in the 15%-20% range — which is competitive with the current state of the art. And the Caltech panel should be far cheaper to manufacture.

Comments

In requires polymer to make...

[assemblerex]

so it is still tied to oil. Becoming cheap and widely popular may do more harm than good I fear.

Re:I think its entirely reasonable to say...

[camperslo]

It sounds like the summary here is overstating the efficiency a bit. The numbers are for the absorption efficiency, not the overall conversion efficiency.

'The light-trapping limit of a material refers to how much sunlight it is able to absorb. The silicon-wire arrays absorb up to 96 percent of incident sunlight at a single wavelength and 85 percent of total collectible sunlight. "We've surpassed previous optical microstructures developed to trap light,"
.
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The silicon wire arrays created by Atwater and his colleagues are able to convert between 90 and 100 percent of the photons they absorb into electrons--in technical terms, the wires have a near-perfect internal quantum efficiency. "High absorption plus good conversion makes for a high-quality solar cell," says Atwater. "It's an important advance."'

It looks like the overall efficiency is still very very high while using minimal resources. This is exactly the kind of innovation the U.S. needs for carbon-friendly jobs.
 

Re:I think its entirely reasonable to say...

[Anonymous Coward]

I saw this posted by grobbo at engadget: http://www.engadget.com/2010/02/28/caltech-gurus-whip-up-highly-efficient-low-cost-flexible-solar/#comments

Turns out the only benefits to this are the flexibility and low cost (which are good, sure, but not that exciting).
According to their letter to nature.com this "also may offer increased photovoltaic efficiency", _may_ suggests to me there probably isn't any significant improvement.

For anyone wondering why high absorption and a high QE don't necessarily result in high energy conversion (like I was a few hours ago) it's because 30% of the photons have insufficient energy to free an electron in silicon, and most of the rest of the photons have more energy than needed to free an electron, so any excess energy beyond that required to free a single electron is wasted as heat.

Re:Absorbed not necessarily equal to electricity

[MaskedSlacker]

Because I don't pay for the nuclear plant or the hydro dam

Yes you do (if you use power from one).

However, getting the money together to buy and install the solar panels is all on me, the homeowner

No it's not. I see/hear ads from solar power rental places all the time (on local media no less, but then again it is Los Angeles). They will do the full install at no upfront, then charge you amortized payments--if the payments are less than what you save on electricity (which their ads claim will usually be the case, for what that's worth, I have no idea if that part's true) then they pay for themselves on day one.

Re:Plastic? 10 years under the sun?

[Khyber]

Saturn vehicles. Body panels are solid plastic, and I know Saturn has been around since the 90s.

Re:Plastic? 10 years under the sun?

[Entropius]

Seconded. I sold a '94 Saturn last year that had been parked in the Arizona sun for many years. (Got rid of it due to multiple electronics failures and an engine oil leak that'd not be worth it to fix). Survived the sunlight just fine.

And the plastic body panels were GREAT. Lightweight and dent-proof.

red light

[timmarhy]

firstly, kdawson your a tard, they aren't 86% efficent at converting light into electricity, merely at absorbing light. the 2nd warning bell for me is this - "The next steps, Atwater says, are to increase the operating voltage " - this sounds to me like they can't produce any meaningful voltages out of these, which is the exact same fail as every other flexible solar panel ever touted. infact they carely avoid talking about it's electrical output at all in TFA.

i'd love cheap energy from the sun, but this won't be it.

Re:It's plastic !

[Enleth]

Ever heard of polycarbonate? They use it to produce composite bulletproof window panes, safety shields for industrial machinery, impact-resistant safety glasses, underwater portholes, etc. It does degrade somewhat under UV light, but then, you can just put an UV filter on top of it, it's not going to be a problem for the panel itself. And there are other transparent plastics with very good properities for this application.

from the ignore-kdawson-the-idiot dept.

[MrVictor]

The original article is poorly written (no, not even close to 86% you stupid twats) and kdawson is equally foolish for echoing this garbage. This is why this site sucks. Brain-dead slashdot editors, time and time again, post shitty articles that make extraordinary claims which end up being completely false or misleading.