The proposition is as idiotic as a plan to generate electricty at a
hydro-electric plant, use that electricity to pump the same water
back into the lake,
and then generate more electrictricy with it.
Whatcha do, see, is connect cables to the upper limbs of white oak
trees, which live for about three hundred years, so plenty of time for
payback. As the trees grow upward the cables pull a lever which
through appropriate gearing turns a wheel which is connected to a
generator, thus producing electricity. Yes, a very small amount of
electricity, as white oak trees do not move upward very fast. But you
do this with millions of trees. Combine all those tiny amounts of
electrical generation together and you would really have something,
eh? (We are going to Canada next week to see our new grandson and I am
practicing my Canada-speak.)