Energy Resources
- Energy resources are large stores of energy that can be used to generate electricity and heat homes and businesses
- 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 resources include:
- Solar energy
- Wind
- Bio-fuel
- Hydroelectricity
- Geothermal
- Tidal
- Non-renewable energy resources include:
- Fossil Fuels (coal, oil and natural gas)
- Nuclear fuel
- 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
- Water can be used to turn turbines in the case of hydroelectric dams, tidal barrages and tidal turbines
- Energy in the kinetic store of the flowing water is transferred to the kinetic store of the turbine and then to the kinetic store of the generator and transferred electrically to the National Grid
A hydroelectric dam transfers energy from the gravitational potential energy store of the water to its kinetic energy store mechanically to turn a turbine
- Fossil fuels can be combusted to heat water, and the steam produced can be used to turn turbines
- Energy from the chemical store of the fuel is transferred to the thermal store of the water, which is then transferred to the kinetic store of the turbine, and then transferred to the kinetic store of the generator and then transferred electrically to the National Grid
The energy transfers involved in the production of electricity from fossil fuels
- Nuclear fuel can also be used to heat water to produce steam to turn turbines
- The energy transfers involved in electricity generation from a nuclear power plant are:
Nuclear store of fuel → thermal store of water → kinetic store of turbine → kinetic store of generator
- Geothermal energy is another way to produce the steam that turns the turbines
- Water is pumped down to the hot rocks and returns through a fissure as steam
Cold water is heated by the rocks and returned as hot water or steam which can be used to turn turbines to generate electricity
- Generating energy reliably requires the use of a range of different energy resources, as listed in the table below:
Energy Resources Table
Worked example
Electricity can be generated by wind power. Describe the energy transfers which occur when a wind turbine is used to generate electricity for the National Grid.
Step 1: Determine where the energy is transferred from
Energy is transferred from the kinetic store of the moving wind...
Step 2: Determine the energy transfer involved as energy is transferred from the wind to the turbine
...to the kinetic store of the turbine as the wind makes it turn.
Step 3: Name the other energy transfers that occur in the process of generating electricity
Energy is transferred from the kinetic store of the turbine to the kinetic store of the generator and is transferred electrically to the National Grid.
