The earth produces a substantial quantity of heat, such as molten rock, volcanic emission, vapors, fog, etc., and the energy available can be combined and utilized by changing into new forms of energy, such as electricity.
Geothermal power stations primarily work on the following three principles:
In the first system hot steam is allowed to directly pass through a compartment having generator turbines, which start rotating under its pressure to generate electricity. The steam ultimately condenses to form water as a byproduct.
In the second type the hot geysers are “flashed" and converted into pressurized steam jet which again is used to run the turbines of an alternator.
The third process also called the binary system incorporates heat exchangers, where the heat from a geothermal source (hot water) is used to heat a second liquid such as isobutene, which has got comparatively low boiling point and therefore is transformed into steam quickly even at ordinary temperatures. The accumulated steam pressure is finally used to drive generator turbines to produce electricity.