Geothermal Steam Power Plant
Steam Power Plants
Dry Steam Power Plants
Dry steam plants use hydrothermal fluids that are primarily steam. The steam travels directly to a turbine, which drives a generator that produces electricity. The steam eliminates the need to burn fossil fuels to run the turbine (also eliminating the need to transport and store fuels). These plants emit only excess steam and very minor amounts of gases.
Dry steam power plants systems were the first type of geothermal power generation plants built (they were first used at Lardarello in Italy in 1904). Steam technology is still effective today at currently in use at The Geysers in northern California, the world's largest single source of geothermal power.
Flash Steam Power Plants
Flash steam plants are the most common type of geothermal power generation plants in operation in the world today. Fluid at temperatures greater than 360°F (182°C) is pumped under high pressure into a tank at the surface held at a much lower pressure, causing some of the fluid to rapidly vaporize, or "flash." The vapor then drives a turbine, which drives a generator. If any liquid remains in the tank, it can be flashed again in a second tank to extract even more energy.
Dry Steam Plants in United States
Flash Steam Plants in United States