Primary energy is energy found in nature that has not been subjected to any conversion or transformation process. It is energy contained in raw fuels as well as other forms of energy received as input to a system.
The concept of primary energy is used especially in energy statistics in the compilation ofenergy balances. It includes non-renewable energy and renewable energy.
Examples of primary energy sources
- Fossil fuels
- Geothermal energy
- Hydro power
- Nuclear fuels (Some nuclear fuels, such as plutonium are not found in nature in any quantity, thus are secondary energy sources.)
- Solar energy
- Tidal energy
- Wave power
- Wind energy
Conversion to secondary energy
Primary energies are transformed in energy conversion processes to more convenient forms of energy, such as electrical energy, refined fuels, or synthetic fuels such as hydrogen fuel. In energy statistics these forms are called secondary energy. Secondary energy is an energy form which has been transformed from another one. Electricity is the most common example, being transformed from such primary sources as coal, oil, natural gas, and wind.
"Primary energy" Wikipedia: The Free Encyclopedia. Wikimedia Foundation, Inc. 07 June 2011. Web. 15 Aug. 2011.