IB DP Physics: SL复习笔记8.1.3 Primary & Secondary Energy Sources

• Primary energy sources are found in nature and have some stored energy capacity
• To be a primary energy source, there must be:
  • No processing or refining
  • Stored energy must occur naturally in the source
• The definition of a primary energy source is:

Energy sources found in the natural environment

• Examples of primary energy sources include fuels such as:
  • oil
  • kerosene
  • coal
  • Nuclear material for fission

• Primary energy sources can also be renewables such as:
  • Geothermal
    • Heat from the Earth's crust
  • Hydroelectric
    • Energy stored in water higher than a set of turbines
  • Solar power
    • Radiation energy from the Sun
  • Wind power
    • Kinetic energy contained within the wind
  • Tidal power
    • Kinetic energy contained within the tides

• In each example listed above, the primary energy source is the focus of the collection
  • Once processing or conversion of energy from one form to another occurs, then it is no longer a primary energy source

• Secondary energy sources come from the use or processing of primary energy sources
• Often the secondary energy source is electricity
  • It can also be petrol, biofuel and heat
• The definition of a secondary energy resource is:

Useful transformations of the primary resources into energy

• Examples include:
  • Stored gravitational energy from water is converted into electricity in a hydroelectric plant.
  • Oil is refined to produce petrol that can be used to power a car
  • Coal is burnt to produce heat on a fire
• The table below shows examples of primary and secondary energy sources as they are used to produce useful energy