Geothermal Electricity Production
In order to function power plants need steam, otherwise they will be unable to produce electricity. At the present moment the majority of power plants use fossil fuels to get the stream from hot water. This is how traditional power plants work. Geothermal power plants use the steam from hot geothermal water from underneath the Earth's surface.
There are the types of geothermal power plants:
Dry Steam Power Plants
This type of plants uses the underground steam to operate. The pipes of the plant are designed in such a way that the steam is delivered to the plant directly and right into the turbines where the electricity is produced. On the territory of the United States there are only two locations where steam in its original form can be reached. One is in the Northern California (the Geysers) and the other is in Wyoming in the Yellowstone National Park. However, with the later being a territory where any kind of such development and activity is forbidden, the only place for dry steam power plant in the U.S. is on the territory of The Geysers.
Flash Steam Power Plants
This type of geothermal power plants is more wide-spread than the other two. Flash stem plants do not use sheer steam to produce energy; they use hot geothermal water that is taken up from under the Earth. Hot underground waters have high pressure levels but as the water goes up the well, its pressure lowers and some of the water turns into steam. This steam is then used by the generators for electricity production. The temperature of such underground geothermal waters usually exceeds 360°F (182°C). The rest of the water then returns back to the reservoir and in this respect geothermal power plants are considered much less harmful for the environment – they produce much less waste.
Binary Cycle Power Plants
This is the most perspective type of a geothermal power plant. Binary cycle plants use hot geothermal water with the temperatures of 225°-360°F. Secondary, or working fluid, is then heated by the hot water. Such fluid has got much lower boiling point than hot spring waters and after being heated, the working fluid vapors and turns into steam that is later used by the generator. The leftover waters get back under the ground for reheating and then the cycle is repeated. It is the most harmless for the environment process possible if compared with the traditional power plants working with fossil fuels.
Small-scale Geothermal Power Plants
It is possible for such small plants (less than 5 megawatts of power) to become the sources of energy in rural areas as they are able to provide sufficient amount of energy and they are also cheaper and less harmful for environment. The most perspective places in the U.S. can be found in Hawaii, the western states and Alaska.