What is Geothermal Energy?
There are many different types of energy available to power our world. For years, people have used the power of burning fossil fuels, such as coal (also used to produce steam power) to create energy. In recent times, there has been a shift to using renewable resources to create the energy we need. These resources include hydroelectric power, solar power, wind power, biomass energy and geothermal energy. While many people know about the first four of these resources, geothermal energy is less well-known.
The word geothermal comes from two Greek words, “geo” and “therme”. These words mean “earth” and “heat”, which pretty much describes what geothermal energy is. Geothermal energy is energy that comes from the heat of the Earth, deep underground. The Earth’s core, where chemical reactions create massive amounts of heat, is 4,000 miles below the Earth’s surface. In this core, temperatures can reach up to 9,000 degrees Fahrenheit, and this extreme heat can be used to produce energy.
While these are the basics of geothermal energy, there are many other parts in the process to make this sort of energy usable. We can’t tap directly into the Earth’s core to receive this heat, for many reasons. So instead, people must create systems that harness the residual heat that is in the magma (molten rock) under the Earth’s crust. This heat is able to be used by tapping into the water reservoirs that are within the magma – these water stores can reach up to 700 degrees Fahrenheit. Think of Old Faithful in Yellowstone.
A well can be drilled down into the superheated water contained within the Earth’s magma – the geothermal reservoir. Once these geothermal reservoirs are tapped into, the heated water and steam can rise to the surface, and be used to power geothermal power plants as well as in smaller scale projects for personal household use. When used in geothermal power plants, the steam from the heated underground water is often used to power turbines, which then generate energy which can be harnessed as electricity.
By using the Earth’s own heat and water, energy can be created that can be used on a small or large scale. This renewable resource (you can’t deplete the Earth’s heat!) is also cleaner and safer than many other types of energy, making it a great type of ecologically sound energy source.
Producing Energy From Geothermal Resources
There are several types of energy used in the world that are considered eco-friendly. These energy types include solar, which harnesses the power of the sun, and hydroelectric, which uses the power of water to generate electricity. One often neglected ecologically sound energy source that should be grouped with the others is geothermal energy. Geothermal energy involves using the Earth’s own heat to create energy and warmth to be used by people.
Geothermal energy is so named because it derives from the Greek words for “earth heat”, “geo” and “therme”. Extreme amounts of heat are generated in the Earth’s core, which reaches temperatures of up to 9,000 degrees Fahrenheit. The Earth’s core then transfers heat to the mantle, a crust of rock surrounding the core. This rock liquefies due to the intense heat becoming magma (molten rock). In this magma layer, water collects in columns or reserves. This trapped water, which can be heated to temperatures of about 700 degrees Fahrenheit, is known as a geothermal reservoir. When engineers want to use geothermal energy, they “tap” in to this geothermal water and use the resulting hot water and steam for various purposes.
Geothermal energy plants work by using the steam resulting from tapping into the geothermal water reservoirs to power turbines. These turbines spin producing electricity which can then be used to power industries or even residential areas. The first geothermically engineered power plant was built in Italy in 1904.
These days, roughly 7000 megawatts of electricity is produced by geothermal power plants per year. Geothermal power plants are located in 21 countries throughout the world. In the United States alone, enough geothermal power is generated per year to be the equivalent to the burning of 60 million barrels of oil making geothermal energy a major source of power.
Geothermal energy has been used by cultures throughout history for thousands of years. The process used to harness geothermal energy has always been relatively simple compared to that of other energy processes, and the components used are familiar to everyone. The concept of using super hot water from the Earth’s magma layers may seem high tech, but once you have tapped into this resource, it is easy to maintain and use as a continual power source.
The best analogy for geothermal energy production is another alternative energy source. It works in the same way as hydropower. Water is used to spin turbines which produce electricity. In the case of geothermal energy, however, the water comes from the internal chambers of the Earth in, most often, the form of steam.