
Originally Posted by
randerizer
Won't respond to all of them, but I just took a class on modern solar cells, so I will respond to this. Current total quantum efficiencies of silicon (or GaAs) solar cells are on the order of 15% at peak daylight. Cost per unit area is very large (we're talking about silicon technologies here, which is certainly the biggest obstacle to being implemented in most cases), and the lifetime of the units with heavy sun exposure is 5-10 yrs at the high end. The improvements on Si and GaAs are slowing - might get to 25% or so, but probably not enough for widespread use. The other option is to make solar cells on plastic, which would lower the costs of the cells. However, efficiencies on plastics are currently on the order of 1%, and the costs aren't cheap enough to make that competitive with Si-technology at this time. Even then, the lifetime of the unit goes down considerably, and the best products have lifetimes on the order of a month.
Plug-ins still require electric power. Currently that's principally coal-driven, which i believe gets lower efficiencies than ICEs.