Abstract: Systems, processes, and non-transitory computer-readable media for use in harvesting heat from subterranean geologic formations. Determining if power produced meets a power target produced by a power plant at selected temperature, pressure, and flow rate of an initial heat extraction fluid. If less than target, flowrate of the fluid is increased, and if more than target, decreasing flowrate of the fluid. If power produced equals the power target, proceed to determine if a producer well pressure would meet a producer well pressure target, and if pressure is less than target, increasing the initial heat extraction fluid pressure, and if the pressure is more than target, decreasing the initial heat extraction fluid pressure. If pressure equals target, flow initial heat extraction fluid from the injector well into and through a first heat extraction stage to form a heated heat extraction fluid, then determining whether a second heat extraction stage is required.