Energy Efficiency

1
Energy Efficiency
2
Efficiency of Energy Conversion

• If we are more efficient with the energy we
  already have there will be less pollution, less
  reliance on foreign oil and increased domestic
  security.

3
Energy Efficiency
Useful Energy Output
Energy Input
Energy Dissipated to the Surroundings
4
Illustration

• An electric motor consumes 100 watts (a joule per
  second (J/s)) of power to obtain 90 watts of
  mechanical power. Determine its efficiency ?
• 90 W x 100 90
• 100 W