Energy transformation facts for kids

Energy from sunlight, water absorbed by the roots, and carbon dioxide from the atmosphere produce glucose and oxygen by photosynthesis

Energy transformations happen everywhere. Energy cannot be created or destroyed and it can't appear from nowhere or disappear. Instead it changes form.

Different situations in nature and some machines can change one form of energy to another.

An example of natural energy conversion is how the Sun is used by plants. During photosynthesis the suns energy is transformed into the chemical energy which is the food for the plants.

An example of a machine making an energy transformation is how wind farm turbines turn mechanical wind energy into electrical energy.

Examples

Examples of sets of energy conversions in machines

A coal-fired power plant involves these energy transformations:

1. Chemical energy in the coal is converted into thermal energy in the exhaust gases of combustion
2. Thermal energy of the exhaust gases converted into thermal energy of steam through heat exchange
3. Thermal energy of steam converted to mechanical energy in the turbine
4. Mechanical energy of the turbine converted to electrical energy by the generator, which is the ultimate output

In such a system, the first and fourth steps are highly efficient, but the second and third steps are less efficient. The most efficient gas-fired electrical power stations can achieve 50% conversion efficiency. Oil- and coal-fired stations are less efficient.

In a conventional the following energy transformations occur:

1. Chemical energy in the fuel is converted into kinetic energy of expanding gas via combustion
2. Kinetic energy of expanding gas converted to the 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
6. Rotary movement passed through a 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

Lamatalaventosa Wind Farm

There are many different machines and transducers that convert one energy form into another. A short list of examples follows:

• Thermoelectric (Heat → Electrical energy)
• Geothermal power (Heat→ Electrical energy)
• Heat engines, such as the internal combustion engine used in cars, or the steam engine (Heat → Mechanical energy)
• Ocean thermal power (Heat → Electrical energy)
• Hydroelectric dams (Gravitational potential energy → Electrical energy)
• Electric generator (Kinetic energy or Mechanical work → Electrical energy)
• Fuel cells (Chemical energy → Electrical energy)
• Battery (electricity) (Chemical energy → Electrical energy)
• Fire (Chemical energy → Heat and Light)
• Electric lamp (Electrical energy → Heat and Light)
• Microphone (Sound → Electrical energy)
• Wave power (Mechanical energy → Electrical energy)
• Windmills (Wind energy → Electrical energy or Mechanical energy)
• Piezoelectrics (Strain → Electrical energy)
• Friction (Kinetic energy → Heat)
• Electric heater (Electric energy → Heat)
• Photosynthesis (Electromagnetic radiation → Chemical energy)
• ATP hydrolysis (Chemical energy in adenosine triphosphate → mechanical energy)

Images for kids

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  Fire is an example of energy transformation

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  Energy transformation using Energy Systems Language

See also

In Spanish: Transformación energética para niños