Solar panel made with ion cannon is cheap enough to challenge fossil fuels

* Difficulty cooling. If you build next to an ocean or river, you can just use some of that water to provide the cold end of the temperature differential that you're using to generate power. Deserts are trickier, and more expensive.

* Transportation. If you build next to navigable waterways, you can ship really big components on barges. In deserts, you can ship some things by rail.

But hey, at least it's politically convenient to stick scary power plants in deserts.

I tried to dig into this a few years ago. Evergreen Solar's 10-K for 2007 http://edgar.sec.gov/Archives/edgar/data/947397/000095013508... has some information. Evergreen's competitive advantage is supposedly that they use less silicon than other manufacturers because they don't saw their wafers — they grow them. They say they use about 5g of silicon per watt (in 2007, planning to reduce it to 2½g per watt by 2012), and it sounds like they get paid about US$3.87 per watt on average (US$58M revenue in 2007, maxed-out manufacturing capacity of 15MW/year, 276 full-time employees in manufacturing). Their "cost of revenue" (i.e. manufacturing cost) was US$53M, or US$3.53/W. But 5g of metallurgical-grade silicon at the price above is US$0.008. If each employee costs US$120k per year (including health benefits, and remembering that a bunch of them are Ph.D.s) then that would be US$2.20/W in labor costs, which already accounts for the majority of that cost of revenue.

But they're not buying metallurgical-grade silicon; they're buying "polysilicon", short for "polycrystalline silicon", which is perhaps a bit of a misnomer, since how many crystals are in each piece of silicon supplied by their suppliers is somewhat immaterial, since Evergreen melts the silicon down and crystallizes it in polycrystalline silicon ribbons in their "String Ribbon" furnaces. Maybe that costs a lot more than metallurgical-grade silicon?

It used to be hard to find that information! But it's much better now; http://pvinsights.com/ lists current PV-grade polysilicon prices at US$29 to US$35 per kilogram, and http://www.pv-tech.org/news/polysilicon_prices_declines_will... explains that this is a major drop from previous prices of US$80/kg. 5 g at US$35 per kilogram is US$0.175. But "Silicon PV Module Price Per Watt" ranges from US$0.75 to US$1.40. Dropping 17½¢ off that price still isn't going to get you to 40¢. And if Evergreen has really made it to 2½g/W, silicon cost is even less of the total cost.

http://www.futurepundit.com/archives/008483.html mentions that in 2008 polysilicon prices peaked at US$400/kg.

Anyway. I'm obviously no expert, but I'm skeptical that peeling silicon with a particle accelerator is going to decrease the cost of photovoltaic cells.

http://www.indiana.edu/~spea/pubs/undergrad-honors/volume-4/...

The key takeaway from that thesis is:

"As determined in the risk characterization, a centralized wind farm does have a greater impact on avian mortality than the coal fired- power plant. "

There are hundreds of other processes with huge energy inputs that are currently satisfied by cheap fossil fuels, but could well be met by equatorial solar facilities. Considering how quickly manufacturing transitioned to China, it seems entirely plausible that we could move most high-energy, low-labour processes to equatorial regions within a couple of decades.