Geothermal energy refers to the heat derived from the surface of the earth. Water or steam carries energy to the surface of the planet. The heat from the earth’s interior generates lava flows, hot springs, and mud pots. The heat is generally produced by the radioactive decay of thorium, potassium, and uranium. The geothermal energy can be tapped and exploited for human use and is available all over the earth. The annual low-grade heat flow to the surface average between 50 to 70 milliwatts. The usable energy varies with the depth and extraction method from geothermal sources.
History of geothermal energy
The geothermal energy is used for cooking and bathing from natural pools and hot springs. The geothermal electric power firstly took place in Larderello. The geothermal energy used by Native Americans for cooking was dated back as early as 10,000 years ago. The uses of geothermal energy were initially limited to the accessibility of hot water and steam. The United States is considered to be the leader in producing geothermal energy. The geothermal energy is used to produce electricity in almost 24 countries.
Uses of geothermal energy
The geothermal energy can be used in three forms: direct-use application, electric power generation, and geothermal heat pumps(GHPs). To produce power, wells are dug deep into the ground to access the steam and hot water there. They can be used to drive turbines which are connected to the electricity generators.
Direct uses
The direct uses of geothermal energy involve the use of heated water from within the ground without the need for any special equipment. The immediate applications make use of low-temperature resources, which range between 50 and 150-degree celsius. Many swimming pools, therapeutic facilities at spas, and aquaculture ponds are heated through geothermal resources. Other uses of geothermal energy include cooking, industrial applications, large scale snow melting, etc.
Geothermal heat pumps
The GHPs are made up of pipes buried in the ground. The heat energy between the ground and air utilizing fluid circulates through pipes. The GHPs take advantage of stable, moderate conditions that occur in the first 300 meters of the surface to heat buildings in winter and cool them in summers. The GHPs have several advantages of conventional heating and air conditioning systems.
Electric power generation
Geothermal energy is used to generate electricity depending upon the temperature and the flow of the stream. The geothermal power plants produce electricity in three different ways. They are efficient and produce less pollution. Up to 72 percent, fewer greenhouse gas emissions are provided by GHPs.
