Other ideas?
Since the old computers will waste tons of electricity, while producing
relatively no cpu power in comparison to a modern CPU chip, you should
use your connected group as a space heater.
Does this even make sense?
Yes. The only 100% efficient electrical appliance, is a heater. Since
by definition, it is supposed to convert electricity into waste, ie,
heat or other forms that eventually will become heat ;)
-Lawrence LeMay