There is a natural source of power found below the surface of the earth that has been around for centuries. Underground, far below us, there are pools of water heated by magma (or molten rocks). These pools of water make up our geothermal reservoirs. Harnessing the power of the earth’s temperatures to power, heat or cool our homes and businesses is the essence of geothermal power. Geothermal Power Plants There are three main types of geothermal energy plants that generate power in slightly different ways.
Dry steam plants are the most common types of geothermal power plants, accounting for about half of the installed geothermal plants. They work by piping hot steam from underground reservoirs directly into turbines from geothermal reservoirs, which power the generators to provide electricity. After powering the turbines, the steam condenses into water and is piped back into the earth via the injection well.
Flash steam plants differ from dry steam because they pump hot water, rather than steam, directly to the surface. These flash steam plants pump hot water at a high pressure from below the earth into a “flash tank” on the surface.
The flash tank is at a much lower temperature, causing the fluid to quickly “flash” into steam. The steam produced powers the turbines. The steam is cooled and condenses into water, where it is pumped back into the ground through the injection well.