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geothermal and fossil energy
Geothermal energy uses the Earth’s internal heat and is a renewable energy source; fossil fuels such as coal and petroleum are nonrenewable energy sources.
A nonpolluting renewable energy source, hydroelectricity accounts for 20% of the electricity consumed around the world.
Large quantity of energy that is released in the form of heat; this occurs during a nuclear reaction (fission of atom nuclei). The heat is used to produce electricity.
Harnessed solar radiation has many applications, including solar-panel heating and electricity produced with solar cells and solar furnaces.
A renewable energy source, wind energy harnesses the power of the wind and converts it into mechanical or electric energy.