Geothermal energy is obtained from hot rocks beneath Earth's surface. The planet's core, which may generate temperatures as high as 8,000°Fahrenheit (4,5007°C), heats its interior, the temperature of which increases, on an average, by about 2°Fahrenheit (1°C) for every 60 feet (18 m) nearer the core. Some heat is also generated in the mantle and crust as a result of the radioactive decay of uranium and other elements.
In some parts of Earth, rocks in excess of 212°Fahrenheit (100°C) are found only a few miles beneath the surface. Water that encounters the rock will be heated above its boiling point. Under some conditions, the water becomes super-heated, that is, is prevented from boiling even though its temperature is greater than...Read more