Geothermal Power Plant

The three plant designs that turn underground heat into electricity from hydrothermal resources of roughly 300 to 700 degrees Fahrenheit. Dry steam plants pipe steam straight from the reservoir to the turbine; flash steam plants, the most common, let high-pressure hot water flash to steam at the surface; and binary-cycle plants pass the heat to a second fluid with a lower boiling point, so the geothermal water itself never touches the turbine and returns to the earth.