How Does Geothermal Energy Work?

Geothermal energy comes from the heat inside the Earth. People can use geothermal energy to heat and cool their homes and to make electricity. The Earth's heat is a clean energy source. It does not cause any pollution. It is also renewable energy. We can't use it up. But how does geothermal energy work?

Much of the Earth's heat comes from its core. It is still hot from when the Earth formed over four billion years ago. Heat from the core spreads outward through the earth's mantle, or middle layer. Inside the mantle, rocks are mostly in liquid form, called magma, melted by the Earth's internal heat. Magma heats the water under the ground. In some places, the hot water shoots to the surface in hot springs and geysers. This hot water can power geothermal energy systems.

Iceland is one place where geothermal energy is used to heat buildings and to grow food. That country has about 25 active volcanoes. Hot springs and geysers are common there, too. Water from hot springs is piped into buildings. The buildings are heated by the water passing through pipes and radiators instead of furnaces that burn coal, oil, or gas.

. . . Print Entire Reading Comprehension with Questions