What is Geothermal Energy
Geothermal energy is energy derived from the heat stored in the earth. This is very different from thermal energy, which is energy that manifests itself from a change in temperature. Geothermal energy originated from the formation of the planet. It continues to regenerate through radioactive decay within the earth, shifting tectonic plates, as well as from the absorption of solar energy at the surface of the earth. Geothermal energy has been used since Roman times when it was used for space heating and bathing. Now, geothermal electric energy is used for district heating, space heating, spas, industrial processes, and various desalination and industrial applications.
Geothermal power is extremely cost-effective, reliable, and environmentally friendly. In the past, geothermal energy was limited to tectonic plate boundaries. More recently this technology has been expanded to larger spaces. Most renewable energies do not release greenhouse gases. Geothermal energy does have the tendency to release greenhouse gases that are trapped beneath the Earth’s surface. However, they release much smaller amounts of gases than that of conventional fossil fuels. Therefore, geothermal energy lessens global warming when used in lieu of fossil fuels.
Geothermal energy has a low impact on the environment. While the energy released from the earth does carry carbon dioxide, hydrogen sulfide, and other mixture of gases with them, geothermal energy is still low on the scale of pollutant energies. Many geothermal plants are equipped with emissions-controlling systems, which can reduce emission intensity as well as exhaust from the various gases.
Hot water from geothermal sources may also have trace amounts of dangerous minerals and elements, including mercury, arsenic, and antimony. The disposal of these in rivers renders the water unsafe to drink for humans as well as animals. Many geothermal plants inject these substances back into the earth to preserve the surrounding environment.
Around 70 countries use geothermal heating. This includes both space heating and energy for heating pools. Industrial and agricultural applications also use geothermal energy. Use of geothermal heat pumps grows by about 10% annually.
The direct application of geothermal heating is much more efficient than the use of geothermal energy used for electricity generation. Direct applications have less demanding temperature requirements, and are also much more viable over a larger geographical range. Natural hot springs allow for water to be pumped directly into radiators. Earth tubes and down-hole heat exchangers can also be used without a heat pump. Heat can be extracted via geothermal heat pumps more efficiently than it can be generated by conventional furnaces.