Geothermal energy has been a resource used by mankind for thousands of years. So, what is geothermal heat?

What is Geothermal Heat

Geothermal energy is based on the natural heat held within the ground below four of five of depth. In essence, the earth maintains a constant temperature roughly five feet under ground and slowly grows warmer as you dig down.

Geothermal energy resources are generally classified according to temperature. High-temperature resources are used for steam and electricity production, medium-temperature for direct space heating and industrial processes, and low-temperature for indirect use with heat pumps.

There are currently two primary uses for geothermal heat as a power source. For high temperature areas, geothermal is used to produce electricity by utilities in power plants. A binary method is used wherein a liquid with a high boiling point is run deep into the ground to absorb heat. Once it has reached a sufficient temperature, it is run back up to the power plant. The hot liquid is then circulated through a liquid with a lower boiling point. When the second liquid boils, the resulting steam is used to turn turbines. The turbines then produce electricity.


The second use of geothermal energy is the heating and cooling of residences. Geothermal heat pumps are used to exchange heat with near surface ground. When the home is hot, the pumps send liquid through coils in the ground to cool off and then convert the energy to cool air which is circulated in the home. In the winter, the opposite process happens with warm liquid coming from the ground being compressed. The compression adds pressure and heat is produced. There are now a variety of geothermal systems for houses, but this is the basic idea.

What is geothermal heat? A cheap, renewable energy source that can be used on both large and small scales to give us relief from fossil fuels and high energy prices.