to give a rough idea on how much difference in output u'd get from the plants, a single geothermal plant can produce 40-170 MW, really dependent on the wells location (some produce only several MW even)
they can compensate this by having multiple plants in a rich area...
the largest i know of is a complex that had 22 plants, with a total of 1500 MW maximum output.
in comparison, a single modern ABWR nuclear plant reactor has a maximum output of 1350 MW, some of the more advanced models in excess of 1500 MW... and that's from one single reactor, a single nuclear power plant usually have several reactors installed.






