What is geothermal energy

For most of the year, California's quest to rid itself of fossil fuels seems on track: Electric cars populate highways while energy from wind, solar and water provides much of the power for homes and businesses geothermal energy, form of Heat from Earth’s interior generates surface phenomena such as see 6 exajoules, or about 1.4 × 10 6 terawatt-years, which equates to roughly three times the world’s annual The amount of usable energy from geothermal sources varies with depth and by extraction method. The increase in Uses Geothermal energy use can be divided into three categories: direct-use applications, geothermal heat pumps (GHPs), and Get a Britannica Premium subscription and gain access to exclusive content. A GHP system is made up of a heat exchanger (a loop of pipes buried in the ground) and a pump. The heat exchanger transfers heat energy between the ground and air at the surface by means of a fluid that circulates through the pipes; the fluid used is often water or a combination of water and GHPs have several advantages over more conventional heating and air-conditioning systems. They are very efficient, using 25–50 percent less electricity than comparable conventional heating and cooling systems, and they produce less Electric power generation Depending upon the temperature and the fluid (steam) flow, geothermal energy can be used to generate

There’s something magical about geothermal energy. A renewable way of generating energy, it builds on an idea going back centuries – using the heat beneath the ground to keep us warm. Widely used in many parts of the world today, it could be expanded in the UK, as we look for more ways to move away from fossil fuels and carbon. But how does it actually work? In this article, we explain the different ways in which geothermal energy is generated, and weigh up its advantages and disadvantages. How does geothermal energy work? The basic idea behind geothermal energy is to tap into underground reservoirs of steam and hot water. This means drilling underground wells of up to a mile deep, and then harnessing the heat to drive turbines and generate electricity. The first time geothermal heat was used to produce electricity was in Larderello, Italy, in 1904 1. But the idea of harnessing geothermal warmth goes back much further – with the Lardarello region known for its hot springs since at least the Roman times. So where’s all this heat coming from? Well, the earth is a bit like an enormous gobstopper. It’s made up of layers that get hotter and hotter as you go down. 1,864 miles deep is the earth’s core 2 – a solid 5,430°C ball (not magma as people often think). It’s as hot as the surface of the sun 4! And why is it so hot down there? Some of the heat was created more than 4 billion years ago when the earth began, and it’s still there today. And new heat is also being created by ra...

Geothermal energy is heat that is generated within the Earth. ( Geo means “earth,” and thermal means “heat” in Greek.) It is a renewable resource that can be harvested for human use. About 2,900 kilometers (1,800 miles) below the Earth’s crust, or surface, is the hottest part of our planet: the core. A small portion of the core’s heat comes from the friction and gravitational pull formed when Earth was created more than 4 billion years ago. However, the vast majority of Earth’s heat is constantly generated by the decay of radioactive isotopes, such as potassium-40 and thorium-232. Isotopes are forms of an element that have a different number of neutrons than regular versions of the element’s atom. Potassium, for instance, has 20 neutrons in its nucleus. Potassium-40, however, has 21 neutrons. As potassium-40 decays, its nucleus changes, emitting enormous amounts of energy (radiation). Potassium-40 most often decays to isotopes of calcium (calcium-40) and argon (argon-40). Radioactive decay is a continual process in the core. Temperatures there rise to more than 5,000° Celsius (about 9,000° Fahrenheit). Heat from the core is constantly radiating outward and warming rocks, water, gas, and other geological material. Earth’s temperature rises with depth from the surface to the core. This gradual change in temperature is known as the geothermal gradient. In most parts of the world, the geothermal gradient is about 25° C per 1 kilometer of depth (1° F per 77 feet of depth). If u...