Re: Solar home panels
Amorphous Silicon PV Cells, have a an "Energy payback" period of averaging 2.2 years. So in effect you get 27.8 years of power "for free" IIRC actual EROEI would be 6.8 (not guaranteeing the math) assuming a maximum life span of 30 years, since there aren’t any A-Si PV’s of that age yet, that’s estimated, however current Mono-Crystalline and Poly Crystalline panels do not currently fail due to the PV cells and have a projected lifespan of 40 years, generally they suffer a mechanical breakage for instance the external housing fails.NREL has some data that corroborates this EROEI and Energy Payback here
Obviously local conditions have an effect on this, and yes I’m ignoring the energy cost of shipping and installation, however whatever the power installation there is some energy cost in shipping and installation, I suspect that in comparision to a coal powered power plant the installation energy cost would be significantly lower, in particular when you consider the maintenance energy cost of mining, and transporting coal to the plant. If someone comes back with data that can prove or disprove this position it would be greatly appreciated.
However to discount this technology as a huge failure at this time is a little premature, since they have a fixed energy cost of creation, and no maintenance energy cost, the overall benefit is definitely positive. Remember too that as we Cross Peak Oil, and other Fossil Fuels the EROEI for extraction begins to increase too, at some point in the future we will hit a point where the energy cost of running that coal plant is so high that just running the plant costs more energy than it produces (i.e. an EROEI < 1).
Iif we keep plugging away at the same energy sources at some point we’re going to reach a point of energy debt where we can no longer climb out of that debt we’ve created at all. I think it far more prudent to consider alternate energy, solar include, to get ourselves out of an energy hole we’re falling into before we reach the same point in energy that correlates to the position we’re in with financial situation. i.e. we can no longer pay our debts.