Quote:
Originally Posted by jjackstone
Found this paper which appears to be a study of studies of Energy Payback Time for energy used of various PV materials. It's only four years old, so fairly recent.
http://astro1.panet.utoledo.edu/~rel...nergy_revs.pdf
The chart on the fifth page shows the energy cost for the various materials. Later, payback times are shown. Their conclusions are about the same as in my earlier post of about a one to four year payback depending on the material used. Dozens of references are given if anyone would like to dig deeper.
JJ |
So it just occurred to me that there are different ways to look at those numbers. On first blush a payback of even the larger number of 4 years seems like a good deal on a solar panel with a 20 year service life. But when viewed in the terms we have always used in assessing fossil fuel extraction, which is ER/EI, a value of 5:1 would be considered economically very marginal.
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But whatever solar and wind and electrification of all systems that we can get built in the next 30 years will be much better than nothing and will be a big help in extending whatever liquid fuel we have left after that.