Don't most energy generating things require expenditure of energy to build?

( Amorous Badger NAKED BEA ARTHUR PHOTOS 4U, Tue 26 Aug 2008, 18:51, archived)

and of course they generate more during their lifetime than they take to build,
otherwise it wouldn't be worth doing at all.
Except for solar power, which is useful for calculators and caravans and satellites and stuff.

When solar cell factories can themselves be solar powered, that will make them more interesting.
( Moon Girl Technologies horrendous beanbag, Tue 26 Aug 2008, 19:04, archived)