Geothermal Energy

3 Pages 784 Words

Geothermal Energy. What is it and how does it produce energy?

Geothermal energy is heat energy that comes from the earth. The source of its energy is molten rock beneath the earth’s surface. It reaches temperatures up to 6000 degrees. This is a result of radioactive core materials decaying. The molten rock and steam reach high pressure and temperatures and is constantly seeking a way out to the surface. In some parts of the world the earth’s crust is very thin and geothermal activity is high. These places are known as “Belts”. Cracks and faults in these areas allow the steam to escape from within the earth. Water finds it’s way down the cracks and the water is then heated. It comes to the earth’s surface as hot springs. The Romans took advantage of this and built bathing places. These were mainly used as healing or pleasure baths because they were thought to have healing powers due to the high mineral content in the water.
It wasn’t until the 19th century that geothermal energy was used for other types of power like electricity. The people of that time did this by creating turbine generators, which harnessed the energy in the steam. The turbine generator was only created because unlike wood, gas and coal geothermal energy could not be used away from its source.

Geothermal energy can be divided into low grade and high grade energy.
Low grade geothermal energy is water, which surfaces between 20 to 80 degrees. Low grade geothermal energy is useful for heating buildings and pools which only need a temperature of 25 degrees to be comfortable in winter.
High grade geothermal energy is not as common and comes to the surface as high pressure steam or hot water over 100 degrees. Fumaroles (Hot Springs that vent steam not water), Geysers (water and steam is shot out at high pressure), Mud Pots (Hot Springs that have so much minerals they look like mud) and Hot Dry Rocks (Underground areas of rock that is...