A hybrid geothermal power system is discussed. The system includes a geothermal system including power plant (101) and pumping station (102) and a nuclear plant (103). Pumping station (102) is used to inject fluid from reservoir (104) through an injection well (105) into the bedrock (106) (also referred to as the hot dry rock HDR zone) and extracted via a secondary bore (extraction well) usually coupled to the power plant (101). In the present example however the injection well is linked to the extraction well (107). As fluid is injected into the bedrock a drop in temperature occurs due to heat transfer to the fluid. Nuclear plant (103) is utilized to combat this drop, the plant (103) has the fissionable components (1091, 1092, 1093) of the reactor positioned within bores (1081, 1082, 1083) within the HDR zone.