Power plants require steam to run the turbines which in turn will activate a generator which produces electricity. However, most of these power plants still use fossil fuels to heat up the water and create steam. Geothermal Energy is produced when we use the hot water springs or the reservoir of hot water found in certain parts on the surface of the earth are utilized to heat up water to create steam to do the needful in generating electricity.

There are three types of geothermal power plants and are discussed as below:

- Dry Steam Power Plants: These energy plants use the steam as it is being produced a few miles under the surface of the earth and is piped into a an apparatus which sometimes pressurizes the steam flow to hit a turbine as to generate the necessary sequence of steps that lead to the production of electricity. Apparently, there are only two such plants in the U.S The northern Californian Geysers and Yellowstone National Park of Wyoming, where there's a well known geyser.

- Flash Steam power Plants: These are the more common variety and are installed at places where underground water exists at very high temperatures in shallow wells. This water is so heated up that they start rising owing to its own pressure and get converted into steam while the uprising. This steam is then captured and then utilized to run turbines and generate electricity.

- Binary Cycle Power Plants: These plants make use of waters at slightly lower temperatures and hence this water is used up to heat another liquid (working liquid) with a very low boiling point, held in a separate container, such that they never get mixed up. This working liquid is transformed into a vapor using a heat exchanger and it is this vapor that is used to turn a turbine to give it the mechanical energy to be able to generate electricity.

Geothermal plants of a slightly smaller scale find a lot of application in rural areas and they are mostly found in parts of the U.S like Hawaii and Alaska.

Geo thermals can be found only at places have some amount of hot streams, hot springs or known reservoirs of hot water pools, even if it is a little below the surface of the earth. Although they provide for a clean, geothermal sources of energy are expensive, huge in size and calls for intensive checking and maintenance. They could never beat the sheer transportability, availability and combustibility of the fossil fuels and even biogas or other such fuels.