Energy Resources (Edexcel IGCSE Physics): Revision Note

Energy resources

• Energy resources in physics are large stores of energy that can be used to generate electricity and heat homes and businesses

  • These are also sometimes called energy sources

Renewable and non-renewable energy resources

• Some electricity drawn from the National Grid is generated from non-renewable resources, and some is generated from renewable resources

• A renewable energy resource is defined as

An energy source that is replenished at a faster rate than the rate at which it is being used

• As a result of this, a renewable energy resource is one that will not run out

• Renewable energy resources include:

  • solar heating panels

  • solar cells

  • wind

  • hydroelectricity

  • geothermal

  • wave

  • tidal

• Non-renewable energy resources include:

  • fossil fuels (coal, oil and natural gas)

  • nuclear fuel

Coal, oil, and natural gas are examples of fossil fuels. These are energy resources in limited supply, meaning they will eventually run out

Generating electricity from energy resources

• Electricity is generated in very similar ways, no matter what energy resource is used

• A turbine is turned, which turns a generator, which generates electricity

• The element that differs is how the turbine is made to turn

• Generating energy reliably on a national or global level requires the use of a range of different energy resources

Energy resources and energy transfers

Wind

• Wind is used to turn turbines directly which turns a generator which generates electricity

• Energy is transferred from the kinetic store of the wind, to the kinetic store of the turbine, to the kinetic store of the generator

Water: hydroelectric

• Water is stored at a height (usually in a dam), and when released, the moving water is used to turn turbines directly which turns a generator, which generates electricity

• Energy is transferred from the gravitational potential store of the water, to the kinetic store of the water, to the kinetic store of the turbine, to the kinetic store of the generator

Water: tidal

• Water is stored at a height (usually by a tidal barrage) at high and low tide, when released the moving water is used to turn turbines directly, which turn a generator, which generates electricity

• Energy is transferred from the gravitational potential store of the water, to the kinetic store of the water, to the kinetic store of the turbine, to the kinetic store of the generator

Water: wave

• The motion of the water due to waves is used to turn turbines directly, which turn a generator, which generates electricity

• Energy is transferred from the kinetic store of the water to the kinetic store of the turbine, to the kinetic store of the generator

Geothermal resources

• Hot rocks underground are used to heat water to produce steam that turns turbines, which turn a generator, which generates electricity

• Energy is transferred from the thermal store of the rocks, to the thermal store of the water, to the kinetic store of the turbine, to the kinetic store of the generator

Solar heating systems

• Solar heating panels use sunlight to heat water in small pipes within the panel to produce warm water for households

• Energy is transferred from the nuclear store of the Sun, to the thermal store of the panel, to the thermal store of the water

Solar cells

• Solar cells use sunlight (EM radiation) to directly produce a current

• When sunlight falls on solar cells, electrons are released from the metal in the solar cell, which can be directed into a circuit, producing a current

• Energy is transferred by radiation from the nuclear store of the Sun, to the thermal store of the solar cell

Fossil fuels

• Fossil fuels are combusted to heat water to produce steam that turns turbines to generate electricity

• Energy is transferred from the chemical store of the fuel, to the thermal store of the water, to the kinetic store of the turbine, to the kinetic store of the generator

Nuclear power

• Nuclear fuels are reacted to heat water to produce steam that turns turbines to generate electricity

• Energy is transferred from the nuclear store of the fuel, to the thermal store of the water, to the kinetic store of the turbine, to the kinetic store of the generator