If you’re coming from Worldchanging, the post with Alex and I discussing long term prospects for cheap solar, and the likely impacts, is here: http://www.worldchanging.com/archives/000510.html

So, there’s basically three or four ways of doing this I’ve been able to track down.

There’s the self-assembling paint on or printable panels coming out of New Jersey:

Mitra and his research team took the carbon nanotubes and combined them with tiny carbon Buckyballs (known as fullerenes) to form snake-like structures. Buckyballs trap electrons, although they can’t make electrons flow. Add sunlight to excite the polymers, and the buckyballs will grab the electrons. Nanotubes, behaving like copper wires, will then be able to make the electrons or current flow.

http://www.sciencedaily.com/releases/2007/07/070719011151.htm

They haven’t made a dollers-per-watt prediction in public but they’re implying radical cost reductions.

Then there are the “quantum dot” solar folks. The approach is somewhat beyond me, but the nutshell is using relatively conventional solar fabrication techniques, possibly including plastic solar cells, but with the energy capture being done by single particles hanging in an isolated quantum state, somewhat akin to bits in a quantum computer. Why this is useful I don’t know, but the efficiency limits are twice or thrice what we have in current solar cells.

http://jobwerx.com/news/Archives/konarka_biz-id=947081_470.html

(that’s talking about quantum dots on plastic, but you can also do quantum dots on silicon.)

Then there’s the “big iron” approach – big solar reflector arrays pointed at Stirling engines.

http://www.stirlingenergy.com/products.asp?Type=solar

In terms of costs, these things are already about competitive with conventional PV. But in terms of manufacturing there’s huge room for price cutting. Dean Kamen (Segway, prosthetic arms etc.) is trying to build economies of scale for the Stirling engines by getting them into hybrid cars as an alternative to the conventional internal combustion engines currently used.

The collector arrays they are using are also really expensive hard engineering. They need something lashed together from bamboo and surfaced with a replaceable mylar tarpaulin.

So that’s a fourth technology pathway. That one is more a series of incremental improvements (say a factor of two or four cost reduction in the Stirling engines, plus a corresponding factor of four for cheaper solar concentrator design.)

Not quite such a radical breakthrough as the new PV cells but “good enough.”

All of these technologies are on much less aggressive schedules than the Korea / Heeger plastic solar panels, hence my usual estimate of “20 years” until we see solar power for 1/2 or 1/4 of the current price of grid power.

http://www.ia.ucsb.edu/pa/display.aspx?pkey=1634
http://www.shortnews.com/start.cfm?id=63637

The Korea / Heeger team, however, put the whole thing so much closer and so much cheaper than we have any reasonable right to expect. I’d be having some serious doubts about it, but Heeger does hold the Nobel for his work on conductive polymers, so he’s a credible guy.

Some random blogger wrote to him to confirm the story:

http://community.livejournal.com/peak_oil/628223.html – Heeger confirms the story is basically accurate, and that they’ll have products for indoor use ready next year.

http://www.technologyreview.com/Energy/19044/ suggests that Heeger’s commercial effort wants to hit 7% efficiency before going after the rooftop market because rooftop real-estate is expensive.

Part of the reason that this isn’t big news is that people love problems, but hate solutions. For all of the focus people are putting on Darfur, the MIT team doing stoves for Darfur get little attention and support. Similarly, people are willing to fight tooth and nail for restrictions and taxes on energy use, but where’s the official paper from Greenpeace saying “this Heeger guy? Give him a blank cheque NOW and let’s innovate our way out of this mess!”

The emotional register is all wrong. It’s a simple story about “man in lab coat saves world” – there’s no conflict, there’s no struggle, there’s no yelling and screaming. Nothing in the typical emotional spectrum of environmentalism. So the story just kind of slips by.

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To put some more context around this.

In 2003, the Massachusetts Institute of Technology (MIT) issued a report entitled, “The Future of Nuclear Power”. They estimated that new nuclear power in the US would cost 6.7 cents per kWh.[1] However, the Energy Policy Act of 2005 includes a tax credit that should reduce that cost slightly.

(from the “new nuclear power plants” article linked in the earlier msg.)

So let’s run numbers for these notional 10 cents per watt panels.

1 kilowatt of panels = $100.

Life of panels? Let’s be conservative: 5 years.

Hours of daylight: Let’s say 8.

300 days a year of sunlight: Arizona.

Kilowatt-hours of electricity generated for your $100 investment: 12000

Cost per kilowatt-hour: 0.83 cents.

Conventional solar panels have a useful lifetime of about 15 – 20 years. My guess is that the plastic panels will be a little less robust but 5 years is low-balling it. If it turns out to be 10 years, we get 0.42 cents per kWh. At 20 years, 0.21 cents.

Now, that only covers daylight power demand – not storage. So odds-are that you have a three phase adoption process: panels go up to cover daylight peak loads in heavy daylight AC areas (i.e. Texas, some of California). Then you see a round of infrastructure to cover night loads and less sunny days – my guess is that you wind up with “pump it back up the hill” hydro or flow batteries or something – or possibly you build some kind of obscene “timeshifting” electricity cable to move power from Africa or the Middle East to America. Superconductors, of course. If that can’t be done economically, then it’ just won’t be done – maybe you ship hydrogen, maybe you just run your night loads off other power sources.

This is really what the fuss is about. We might be five years away from electricity in sunny areas in day time costing 1/10th of what it does now. Changes the whole game.