top of page

Energy Conservation and Efficiency

Conservation of Energy and Wasted Energy

  • Energy cannot be created or destroyed, just transferred to other stores

  • Energy that is not usefully transferred is wasted, often this is dissipated to the surroundings: increasing their thermal store

Isaac Physics GCSE Online 2022.png
Worksheet Only.png


Efficiency is the ratio of the increase in the useful energy store (output) to the energy in the original store (input). This can either be expressed as a number between 0 an 1, or as a percentage.

Reducing Unwanted Energy Losses

Reducing unwanted energy losses can be achieved in many ways, including:

  • by thermal insulation

  • by lubrication

Sankey Diagrams

These are a great way to visualise the energy transfers in a device and therefore its efficiency.

You may also be interested in...

Click below to return to your exam board

bottom of page