Energy conversion 

Energy Transformation in Energy Systems Language

In physics and engineering, energy transformation, energy transfer, energy conversion or power transfer, is any process of transforming one form of energy into another. Energy of fossil fuels, solar radiation, or nuclear fuels can be converted into other energy forms such as electrical, propulsive, or heating that are more useful to people. Often, machines are used to transform energy. The efficiency of a machine characterizes how well (how efficiently) it can produce a useful output (such as work for example) through such a conversion. Energy transformations are important in the application of the energy concept in various natural sciences including biology, chemistry, geology and cosmology.

In chemistry, the term may be used to describe the process of transferring vibrational energy from one molecule (or molecular domain) to another molecule (or molecular domain).

Energy may be transformed so that it may be used by other natural processes or machines, or else to provide some service to society (such as heat, light, or motion). For example, an internal combustion engine converts the potential chemical energy in gasoline and oxygen into the propulsive energy that moves a vehicle. A solar cell converts solar radiation into electrical energy that can then be used to light a bulb or power a computer. The generic name for a device which converts energy from one form to another is transducer.

Examples

For instance, a coal-fired power plant involves these power transfers:

  1. Potential energy in the coal converted to thermal energy
  2. Thermal energy converted to kinetic energy in steam
  3. Steam energy converted to mechanical energy in the turbine
  4. Mechanical energy of the turbine converted to electrical energy, which is the ultimate output

In such a system, the last step is almost perfectly efficient, the first and second steps are fairly efficient, but the third step is relatively inefficient.

In a conventional automobile, these power transfers are involved:

  1. Potential energy in the fuel converted to kinetic energy of expanding gas via combustion
  2. Kinetic energy of expanding gas converted to linear piston movement
  3. Linear piston movement converted to rotary crankshaft movement
  4. Rotary crankshaft movement passed into transmission assembly
  5. Rotary movement passed out of transmission assembly in second step
  6. Rotary movement passed through differential
  7. Rotary movement passed out of differential to drive wheels
  8. Rotary movement of drive wheels converted to linear motion of the vehicle

Other energy conversions

There are many different machines that convert one energy form into another: