Geothermal heat refers to the heat retained inside the Earth's surface. The term has been derived from the Greek words, geo for Earth and thermos for heat. As per evidence, heat energy in the deep underground, results from the decay of radioactive particles and absorption of solar heat. The average temperature is 50 - 70 degrees Fahrenheit. It can be used as an alternative energy source for heating homes and household appliances.
Geothermal heating is a new technology, implemented for solving the global energy crisis. It makes use of geothermal energy, for heating or cooling applications. As of now, it has succeeded in providing more than 0.07 percent of the worldwide energy consumption. In a geothermal heating system, the heat energy stored inside the Earth's surface is used for heating purposes. It is also referred to as ground source heat pump. A standard system has the capacity to warm up a building without using other heating appliances.
For better understanding of the working of a geothermal heating system, first let's discuss its main components. In this heating system, there are three primary parts, namely, a geothermal heat pump, ground loop system, and a distribution system. The heat pump is installed inside the house or property, while the ground loops or pipes are configured under the Earth's crust at a specific depth. The depth of the piping depends upon the potency and degree of availability of geothermal heat in the particular area.
The pipes of the ground loop are connected to the geothermal heat pump and the distribution system is configured as per the requirement of the user. The heat pump forces a liquid refrigerant or cool water into the pipes of the ground loop, which is then circulated underground. The refrigerant is warmed up naturally due to heat inside the Earth's surface. The heated water is circulated back to the heat pump that exchanges the heat by using a heat exchanger. This heat exchanger then circulates warm air inside the house via the distribution system.
Speaking about the use in warmer months, it can be operated for cooling a house similar to air conditioners. The functioning principle of the system is reversed, so that the heat exchanger now supplies cool air in the house. For setting the desired temperature, an electronic thermostat is configured in the system, which heats or cools the house accordingly.
Since the heat exchanger is operated by using electricity, the overall working of a heating system, consumes some amount of energy. Nevertheless, it is very cost-effective to use geothermal heating in comparison to other systems. These systems are more successful in areas that lie near the plate tectonic boundaries. Over these regions, the heat-laden magma often rises near to the Earth's surface. In such cases, it can be effectively used for heating water.
One of the major advantages of geothermal energy is that it is renewable and eco-friendly. It is renewable since heat trapped inside the Earth's surface can be used for both heating or cooling purposes. Also, unlike other conventional heating appliances, operation of a geothermal one does not emit toxic gases or pollutants.