A system, apparatus and method for generating electricity from renewable geothermal, wind, and solar energy sources includes a heat balancer for supplementing and regulating the heat energy fed to a turbine generator; a hydrogen-fired boiler for supplying supplementary heat; and an injection manifold for metering controlled amounts of superheated combustible gas into the working fluids to optimize efficiency. Wind or solar power may be converted to hydrogen in an electrolysis unit to produce hydrogen. A phase separator unit that operates by cavitation of the geothermal fluids removes gases from the source fluid. A pollution prevention trap may be used to remove solids and other unneeded constituents of the geothermal fluids to be stored or processed in a solution mining unit for reuse or sale. Spent geothermal and working fluids may be processed and injected into the geothermal strata to aid in maintaining its temperature or in solution mining of elements in the lithosphere.