(i) What is geothermal energy?

(ii) How is geothermal energy used to produce electricity?

(i) Geothermal energy is the heat energy contained in the rock and fluid that fills the fractures and pores within the rock in the earth's crust.

(ii) Resources of geothermal energy can be generated by using the shallow steam, hot water and hot rock by drilling wells up to thousands of feet beneath the earth's surface. The extremely high temperatures in the deeper geothermal reservoirs are used for the generation of electricity. The high-pressure steam spins the turbine that rotates a generator and produces electricity.

Hot water is pumped from deep underground through a well under high pressure. When the water reaches the surface, the pressure is dropped, which causes the water to turn into steam. The steam spins the turbine, which is connected to a generator that produces electricity. The steam cools off in the cooling tower and condenses back to water. The cooled water is pumped back into the earth to begin the process again.