is that 2.1 cents a kwh? Dirt cheap.

I've read that solar panels (I have one for hot water) might lose some efficacy over the decades but even those installed 40 years ago are still working. I guess at some point it will be cost effective to replace them...or if the math works out leave them working at, say, 60% efficiency, and build a new one. It's not like they're running out of sunny places over there.