What is Geothermal Energy?
The interior, or core, of the Earth is very hot. This heat sometimes reaches the Earth’s surface through volcanoes or geysers. When we use the heat of the earth to generate energy, it is called geothermal energy. The name geothermal is a combination of the words “geo” meaning earth and “thermal” meaning heat. sustainable energy
Sustainable Energy
The earth is constantly warming by its core. When we use geothermal energy, we don’t deplete resources like when we burn gas or coal. Although we use a very small fraction of the Earth’s heat, it’s a very small amount compared to the Earth’s overall heat. This makes geothermal energy a sustainable energy.
Geothermal power plants are very clean and have little negative impact on the environment.
How do we get power from the Earth?
There are three main ways that we harness and use geothermal energy:
Geothermal Heat Pumps – At a depth of about 10 feet below the Earth’s surface, the ground has a constant temperature between 50 and 60°F throughout the year. Geothermal heat pumps take advantage of this constant temperature to heat or cool water. By moving water across the Earth, it can be heated in winter or cooled in summer. This water can then be used by a heat exchanger to heat or cool the indoor air. It can be a very efficient and inexpensive way to heat or cool buildings.
Direct Use – Another way to take advantage of the Earth’s heat is to directly use hot water from hot springs. This water can be used with heat exchangers to heat homes and buildings. It can also be used to heat swimming pools.
Generating Electricity – Finally, geothermal energy can be used by power plants to generate electricity. Power plants take advantage of extremely hot water that lies one to two miles underground. Some power plants supply steam directly to generators. These are called dry steam power plants. Other power plants, known as rapid steam plants, use high pressure from deep within the Earth to generate steam that drives generators.
History of Geothermal Energy
The use of geothermal energy is not new. People have been using hot springs since ancient China. The ancient Romans took this concept a step further and used hot springs to heat floors and public baths.
The first use of geothermal energy to produce electricity dates back to 1904 when the geothermal generator was invented. A few years later, in 1911, the first geothermal power plant was built. In the 1940s, heat pumps began to be used to heat buildings, but it only became popular after the oil crisis of the 1970s.
Are there any drawbacks to Geothermal Energy?
The main disadvantage of geothermal energy is probably its cost. It can be very expensive to build a geothermal power plant. Building a power plant can also be risky for a power company, as steam is likely to run out at a given location. The main environmental disadvantage is the possibility of releasing toxic gases when drilling wells into the ground.
Fun Facts about Geothermal Energy
The majority of geothermal power plants in the United States are located in the western part of the country. California is the top producer, followed by Nevada, Utah, Hawaii and Idaho.
The United States is the largest producer of geothermal electricity.
In 2011, the Philippines produced about 16% of all electricity using geothermal power plants. Iceland produces 26% of all electricity using geothermal energy. Geothermal power plants can cause earthquakes.
The best place to find geothermal resources is along plate boundaries.