Journal of Fundamentals of Renewable Energy and Applications
Open Access

Geothermal Energy

Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. The geothermal energy of the Earth's crust originates from the original formation of the planet and from radioactive decay of materials 

Geothermal energy is heat derived within the sub-surface of the earth. Water and/or steam carry the geothermal energy to the Earth's surface. Depending on its characteristics, geothermal energy can be used for heating and cooling purposes or be harnessed to generate clean electricity.

Geothermal energy (from the Greek roots geo, meaning earth, and from thermos, meaning heat) is energy made by heat inside the Earth's crust. ... When used to generate electricity, geothermal power plants typically offer constant output.

Geothermal power plants use steam to produce electricity. The steam comes from reservoirs of hot water found a few miles or more below the earth's surface. The steam rotates a turbine that activates a generator, which produces electricity

Geothermal power plants are associated with sulfur dioxide and silica emissions, and the reservoirs can contain traces of toxic heavy metals including mercury, arsenic and boron. Regardless of how we look at it, the pollution associated with geothermal power is nowhere near what we see with coal power and fossil fuels.