Technology Review has an article on thin-film solar, mostly focusing on First Solar. This stuff is very, very close to competitive with conventional solar panels and on a clear path to being competitive with traditional fossil-based electricity sources. It’s an exciting time.
Speaking of solar excitement: A team at the Univ. of Delaware has just broken the previous world record for solar cell efficiency. The previous record was 40.7% efficiency, held by the Defense Advanced Research Projects Agency (DARPA). The UD team hit 42.8%. They’re shooting for 50%.
Skeptics point out that solar power has been "on the verge of a revolution" for about 30 years now, so I realize I risk mockery when I say this, but nonetheless, this time it really does seem true that … solar power is on the verge of a revolution.
Check back in five years. If I was wrong, mock away.