Energy supply

Energy supply is the total amount of usable energy accessible to people for doing work. We use forms of energy to activate machinery; to heat and cool our homes and offices to cook to provide light and to carry people and goods. Heat energy is the most frequently used outline of energy.

Energy may be obtained openly from an energy source, as when people flame wood to fabricate heat. Energy may also be obtained indirectly. For example, at a power plant, oil is burned to create steam and that steam produced is used to power a generator which is used for electricity.
Energy that is shaped by businesses and the government and then sold to the public is called marketable energy. About 85 percent of all marketable energy comes from petroleum, coal, and natural gas. Petroleum, coal, and natural gas are called fossil fuels because they developed from the fossilized ruins of prehistoric plants.