Below the Earth’s surface there are huge reserves of the Geothermal Energy. The word “geothermal” comes from the Greek words Geo – it means earth and Therme – means heat. It is thermal energy created in the Earth’s crust with slow decay of radioactive elements (by chemical reactions or friction during movement of tectonic plates). The amount of such energy is so great that it can be considered almost inexhaustible, and therefore it is a renewable source of energy.
For the exploitation of geothermal energy are the best areas where the hot mass is close to the earth’s surface. On many such locations in the world, there are already different thermal plants. In this way, the heated water is used for space heating or for industrial purposes.
Some disadvantages and advantages of geothermal energy
The biggest drawback is that there are not many suitable locations in the world for the exploitation of this energy and convenient for the construction of geothermal power plants. It is impossible to transport the geothermal energy, and therefore it can only be used for heat supply of nearby places. Another big problem is the discharge of materials and gases from the depths of the earth. They can be harmful when they come to the surface (hydrogen sulfide is particularly dangerous).
Geothermal sources have many advantages over traditional sources of energy based on fossil fuels. The biggest advantage of geothermal energy is that it is clean and safe for the environment. The methods, which are used to generate electricity, do not produce harmful emissions to our environment. Another advantage is a huge stock of energy at our disposal (they are practically inexhaustible). Also, geothermal power plants occupy a small space. This energy is reliable because it does not depend on meteorological influences unlike hydropower.
The use of geothermal energy
Geothermal sources have been used since ancient times. Electricity generation by geothermal energy sources started since 1913. However, a significant increase in its use was observed in the last three decades.
The main areas of application are:
- Production of electricity
- Space heating
- Paper production
- Pasteurization of milk
- For swimming pools and thermal baths
- In the process of the wood drying
- For animal husbandry and farming
Space heating – Geothermal energy has been used for building heating since the time of the Roman Empire. In recent years, the term geothermal heating refers to heating and cooling by special pumps. Such geothermal systems are able to transfer heat from the ground with minimal power consumption. The largest geothermal heating systems are located in Iceland.
Electricity production – One of the most significant forms of geothermal exploitation is electricity production. It uses hot water and steam from the earth to run the generators. So, there is no burning of fossil fuels, and as a result, there are no harmful emissions into the atmosphere (it emits only water vapor).
Geothermal Energy is mostly used in Iceland. About 19.1% of electricity in Iceland is derived from geothermal sources. In addition to Iceland, the largest users are: USA, Italy, Germany, France, New Zealand, Russia, Philippines, Indonesia, China, Japan and many others. Unfortunately, some states don’t use all the available potential. The World’s geothermal potential is enormous, but only a small part can be effectively exploited – to a depth of 5000 m.