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

Hint: Geothermal energy is heat that exists within the earth's crust. Geothermal is derived from the Greek words geo (earth) and therme (heat) (heat). Because heat is constantly created inside the ground, geothermal energy is a renewable energy source. Geothermal heat is used for bathing, heating houses, and generating energy.

Complete answer:
(a).The thermal energy created and stored in the Earth is known as geothermal energy. The energy that determines the temperature of matter is known as thermal energy. The geothermal energy in the Earth's crust comes from both the planet's creation and the radioactive decay of minerals (in currently uncertain but possibly roughly equal proportions).
(b).The Earth's core thermal energy flows to the surface at a rate of 44.2 terawatts (TW) through conduction and is replenished at a rate of 30 TW by radioactive decay of minerals. These power rates are more than twice humanity's present energy consumption from all main sources combined, however the vast majority of this energy flow is unrecoverable. In addition to internal heat fluxes, solar energy heats the top layer of the surface to a depth of 10 m (33 ft) in the summer, then releases that energy and cools in the winter.
(c).The subsurface water is heated and turned into steam by hot rocks deep within the earth. As additional steam forms between the rocks, it is crushed to extremely high pressures. A pipe is inserted into a hole bored into the soil up to the heated rocks. The high-pressure steam that surrounds the rocks rises through the pipe, turning the turbine of a generator and producing power.
(d) Geothermal energy's benefit.
It is highly cost effective to use.
(ii) It does not pollute the environment.
(e) Geothermal energy's drawbacks
It is not widely distributed.
(ii) Deep drilling in the ground is necessary, which is both technically and financially challenging.

Note:
In 75 nations, sources with temperatures ranging from 30 to 150 °C are utilised as district heating, greenhouses, fisheries, mineral recovery, industrial process heating, and bathing without converting to electricity. In 43 countries, heat pumps capture energy from shallow sources at 10–20°C for use in space heating and cooling. Home heating is the fastest-growing geothermal energy use, with a global annual growth rate of 30% in 2005 and 20% in 2012.