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Solar Power Play
dpilgrim writes "While American power companies continue to chase vanishing oil reserves, the Japanese are once again a step ahead in innovation. Reuters is carrying this story about Sharp's new manucfacturing plant in the U.S. Sharp will begin manufacturing solar batteries stateside, and expects more than half its solar battery sales to be in the U.S. by 2004. Looks like a good use for that south-facing hillside on my property."
Photovoltaic systems still have a long way to go to become economical enough to compete with more conventional methods.
You get about 100 watts of solar radiation per square foot (perpendicular to the sun's rays). Current commercial PV cells are, at best, 15% efficient.. so now you have 15 watts of electricity per square foot.
A conventional powerplants generate roughly 500-1000 Megawatts each. Doing the math, you'ld need well over 32 million square feet of collection area to match that... roughly 765 acres of active surface. PV arrays can't be packed together either, because they would cast shadows on eachother... so the actual real-estate required would be 4 or 5 times that!
Even if the PV cells were *free*, the cost of installation, service, and the land itself would be astronomical! There's no way a solar farm could pay for itself.
Nobody is going to stop burning coal and oil anytime soon (unless they run out!)
Not to say PV cells don't have their uses, of course. Cheap PV panels can certaintly help ease the energy budget!
=Smidge=
My guess is that they are referring to a 3kW cell array. The ROI would be primarily a factor of how much power you use during daylight hours.
Without the tax incentives, it would be hard to see a 10-year simple payback, unless there are significant costs associated with hooking up to the power grid (namely distance).
Compared to a 3kW diesel generator... it has an ROI. Compared to $0.10/kWh... not yet!