Question

(a) What is geothermal energy?
(b) What is the source of heat contained in geothermal energy?
(c) Explain how, geothermal energy is used to generate electricity.
(d) State two advantages of geothermal energy.
(e) State two disadvantages of geothermal energy.

Answer 1

(a) Geothermal energy

Geothermal energy is the heat energy obtained from the fission of radioactive materials present in the hot rocks inside the earth.

(b) The hot rocks present below the surface of the earth are the sources of the heat provided by geothermal energy.

(c) The hot rocks inside the earth heat the underground water and turn it into steam. As more and more steam is formed between the rocks, it gets compressed to high pressures. A hole is drilled into the earth up to the hot rocks and a pipe is put into it. The steam present around the rocks comes up through the pipe at high pressure, which turns the turbine of a generator and thus produces electricity.

(d) Two advantages of geothermal energy are given below.
1. It is economical to use.
2. It does not cause any pollution.

(e) Two disadvantages of geothermal energy are given below.
1. It is available only in areas where there are hot rocks near the surface of the earth.
2. Deep drilling into the earth to obtain geothermal energy is technically very difficult and expensive.