Geothermal
Geothermal energy is energy from the heat of the earth. It has been used for thousands of years in some countries for hot water, cooking and heating. It can also generate electricity using steam produced from heat found beneath the surface of the earth.
The centre of the earth is hot enough to melt rock. Even at relatively shallow depths of a few kilometres, the temperature can be well over 250 degrees Celsius. In addition, in volcanic areas, melted rock can come up to, or very close to the surface itself.
Geothermal power plants, like wind and solar power plants, do not have to burn fuels to manufacture steam to turn the turbines. Generating electricity with geothermal energy helps to conserve nonrenewable fossil fuels, and by decreasing the use of these fuels, we reduce emissions that harm our atmosphere. There is no smoky air around geothermal power plants -- in fact some are built in the middle of farm crops and forests, and share land with cattle and local wildlife.
For more details on Geothermal follow the link
