What is geothermal energy? what are its advantages and disadvantages?

a:
geothermal energy is energy from coal, natural gas, and other rocks; it pollutes the environment, but it is inexpensive.

b:
geothermal energy is energy from the earth’s core; it pollutes the environment, is very expensive, but can be used anywhere in the world

c:
geothermal energy is energy from the earth’s interior; it produces little pollution, but it is limited to certain geographical areas.

d:
geothermal energy is heat energy from a turbine that spins from wind; it produces little pollution, but it is very expensive

A: There are many advantages of geothermal energy. It can be extracted without burning a fossil fuel such as coal, gas, or oil. ... Unlike solar and wind energy, geothermal energy is always available, 365 days a year. It's also relatively inexpensive; savings from direct use can be as much as 80 percent over fossil fuels. Geothermal power plants use steam to produce electricity. The steam comes from reservoirs of hot water found a few miles or more below the earth's surface. The steam rotates a turbine that activates a generator, which produces electricity.

B: Geothermal energy is clean because it can be generated without burning fossil fuels. ... The initial costs of geothermal energy are high -- wells can cost $1 to $4 million each to drill, and installation of a home geothermal pump system can run as much as $30,000 [sources: REPP, Consumer Energy Center]. Wave power converts the periodic up-and-down movement of the oceans waves into electricity by placing equipment on the surface of the oceans that captures the energy produced by the wave movement and converts this mechanical energy into electrical power.

C: Geothermal power plants emit 97% less acid rain-causing sulfur compounds and about 99% less carbon dioxide than fossil fuel power plants of similar size. ... This recycling helps to renew the geothermal resource and to reduce emissions from the geothermal power plants. Hydroelectric power is considered to be an example of multiple transfers of energy because potential energy when the water is in the reservoir turns into kinetic energy making the water move to the dam and then the dam moves into the turbine turning it to electric energy.

D: When geothermal power plants do emit gases, it's mostly carbon dioxide, which isn't a pollutant but a greenhouse gas. Still, geothermal power plants emit much less carbon dioxide than fossil fuel power plants.

Explanation:

This energy source is more environmentally friendly than conventional fuel sources. The largest single disadvantage of geothermal energy is that it is location specific. A source of renewable energy. ... A reliable source as its easier to predict the power output from a geothermal plant with a high degree of accuracy.