Nanosolar, a company supported by Larry Page and Sergey Brin (the founders of Google), has announced that it will be selling thin-film solar cells profitably for $1 a watt. Apparently, the cells are printed with copper indium gallium selenide – an alternative to silicon. Cells based on the material can convert solar radiation to electricity with 19.5% efficiency. In theory, this material can applied to foil, plastic, glass or cement – producing electricity generating surfaces. It can also be made into more conventional panels of the sort Nanosolar is starting to sell.
In the 1950s, solar cells cost about $200 per watt. By 2004 they were down to $2.70. Further reductions could make solar power cost competitive with fossil fuels, potentially even in the absence of carbon pricing. Combined with either better storage (to moderate light/dark and sunny/cloudy cycles locally) or better inter-regional transmission (the sun is always shining somewhere), such cells could eventually make a big difference in the overall energy balance. Solar has been discussed here previously.