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 originates from the original formation of the planet, as well as from the absorption of solar energy which is absorbed at the surface of the earth. Geothermal energy is currently used for generating electricity. Geothermal electric energy is used for district heating, space heating, spas, industrial processes, and various desalination and industrial applications.
In the past, geothermal energy has been limited to tectonic plate boundaries. More recently this technology has been expanded to larger spaces. Most renewable energies do not release greenhouse gases, however geothermal energy does have the tendency to release greenhouse gases that are trapped beneath the earth’s surface. Geothermal energy releases much smaller amounts of greenhouse gases than that of the conventional fossil fuels. Therefore, geothermal energy lessens global warming when used in lieu of fossil fuels. It has been theorized that the negative minerals removed from the earth in the geothermal process can be injected back into the earth, solving the problem of their pollution.
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, geotherma
l 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. Geothermal energy is renewable, however geothermal sites can be exhausted if they are overused. This is a very expensive mistake to make.
Thermal energy, on the other hand, is not manifested from the earth. Instead, it is found
in the increase of temperature generated from the sum of sensible heat and latent heat. Solar thermal energy refers to using solar energy (the renewable energy generated from the sun) for thermal uses. This energy is completely renewable, which could solve worldwide energy problems.
Solar energy is harnessed through low, medium, and high solar collectors. Each applies the concept of thermal
energy generation in various ways. Low temperature collectors are flat plates, which are generally used to heat swimming pools. Medium temperature collectors are also flat plates, but instead are used for commercial and residential hot water heating. High temperature collectors differ immensely from low and medium collectors, as they don’t use plates. Instead, high temperature collectors use mirrors and lenses to concentrate sunlight. This form of collecting is generally used for electric power production. It is important to keep in mind that solar thermal energy generates a different kind of energy than photovoltaics.