The word geothermal literally means heat from within the earth. At its simplest, geothermal energy is power extracted from heat within the earth’s crust. Very deep within the earth is a layer of molten rock known as magma, from which heat is continually produced through the natural decay of uranium, potassium and other radioactive materials. The layers of rock surrounding this magma are super-heated, gradually declining in temperature as you move farther from the molten core and toward the relatively chilly surface.
Erupting volcanoes are an example of magma exploding through chambers connected to this molten layer, usually by way of seismic activity. So it stands to reason that areas with high volcanic or seismic activity have the highest geothermal resources. Yet geothermal energy is everywhere. According to the Union of Concerned Scientists, the amount of heat within 33,000 feet of the earth’s surface contains 50,000 times more energy than all the oil and gas resources in the world.
Is Geothermal Energy Renewable?
Geothermal power is not inherently a renewable resource; a geothermal resource can be depleted. However, proper plant management can transform geothermal power into a renewable resource. The key is to avoid removing more super heated water than can be replenished by natural processes or through re-injection of used water resources. (more…)