Geothermal power means getting [?] from [?] rocks underground. This is [?] so long as we don't take too much energy out and cool the rocks too much.

Hot [?] comes up out of the hole we've drilled and usually "flashes" into [?]. This can drive turbines and generators, to make [?].

At some sites we have to [?] water down, at others hot water comes up anyway. Sometimes poisonous [?] come up too.

Geothermal power can occasioanally be unreliable, and there are not many suitable [?] because there needs to be the right type of [?] at a [?] we can reach, underneath rock which isn't too hard to [?] through.