Energy harnessed from the earth is known as geothermal energy and provides a clean renewable alternative to fossil fuel derived energy. Sources of geothermal energy from underground can range from 10 feet below the earths surface to miles deep underground where temperatures melt rock into liquid magma.
Almost everywhere, the shallow ground or upper 10 feet of the Earth’s surface maintains a nearly constant temperature between 50° and 60°F (10° and 16°C). Geothermal heat pumps use this source of renewable energy and convert it into a usable form of energy to be used in domestic or commercial buildings for space and water heating. The heat pumps consist of a heat pump an air delivery system and a heat exchanger, which is a system of coiled pipes that are buried in the ground located near the building. During the winter months the heat exchanger extracts the heat from underground and transfers it via the pump into the building. In the summer it works in reverse by removing heat from the building and transferring into the ground.
Geothermal energy is also capable of powering turbines to produce electricity.
Steam from an underground well is used to power a turbine thus generating electricity. Boiling hot water from an underground source is also used. Direct-use applications include heating buildings, growing plants in greenhouses, drying crops, heating water at fish farms, and several industrial processes such as pasteurizing milk.
Deep beneath the earth hot dry rock is being accessed to extract geothermal energy. Water is injected down to the hot dry rocks where it super heats and then extracted again to be used. The water is then re-circulated back down to the well where it is super-heated and the process starts over again. There are many technologies available today developed to make use of geothermal energy. It is estimated within a very short time the world will reach the maximum capacity of oil production in the world. It is reassuring to note that when this happens, there are renewable technologies available that can provide the heating requirements for our homes.