Comparing Energy Resources (Edexcel IGCSE Physics): Revision Note

Comparing energy resources

• All energy resources have advantages and disadvantages associated with them

• A renewable energy resource is one that is replenished at a faster rate than the rate at which it is being used

  • As a result of this, renewable energy resources will not run out

• A reliable energy resource is one that can produce energy at any time

• Unreliable resources can only produce energy some of the time (e.g. when it's windy)

Fossil fuels

Advantages of fossil fuels:

• Reliable — produces large amounts of energy consistently

• Can respond quickly to changes in demand

Disadvantages of fossil fuels:

• Non-renewable — supplies will eventually run out

• Produces carbon dioxide (CO₂), which contributes to global warming

• Produces sulphur dioxide, which causes acid rain

Nuclear

Advantages of nuclear power:

• Reliable — produces large amounts of energy consistently

• Produces no greenhouse gases or CO₂ during electricity generation

• Large amounts of energy are produced from small amounts of fuel

Disadvantages of nuclear power:

• Produces radioactive waste that takes thousands of years to decay and must be safely disposed of

• Risk of nuclear accidents, which can have catastrophic consequences

• Non-renewable — uranium supplies will eventually run out

• Nuclear power stations are expensive to build and maintain

• Nuclear power stations take many years to build

• Cannot be turned on or off quickly, so cannot respond to changes in demand

Biofuels

Advantages of biofuels:

• The CO₂ released from combustion is balanced by the CO₂ absorbed in photosynthesis, so could be considered carbon neutral

Disadvantages of biofuels:

• Crops grown for biofuels compete with food crops for land and resources

• Combustion still releases CO₂ at the point of use

• Deforestation to clear land for crops can release stored carbon and destroy habitats

Wind

Advantages of wind power:

• Renewable — will not run out

• Produces no greenhouse gases or pollution during operation

• No fuel costs and low running costs once built

Disadvantages of wind power:

• Unreliable — only generates electricity when the wind is blowing at sufficient speed

• Visual pollution — wind turbines can spoil the view of the landscape

• Can produce noise pollution

• High initial cost to build

Hydroelectric

Advantages of hydroelectric power:

• Reliable

• Can respond quickly to changes in demand

• Produces no greenhouse gases or pollution during operation

• No fuel costs

Disadvantages of hydroelectric power:

• Building reservoirs can flood large areas, destroying habitats and displacing wildlife

Tidal

Advantages of tidal power:

• Reliable — tides are very predictable, so energy can be produced at regular intervals

• Produces no greenhouse gases or pollution during operation

• No fuel costs

Disadvantages of tidal power:

• Few suitable locations (estuaries)

• Can harm aquatic life and disrupt shipping

Geothermal

Advantages of geothermal power:

• Reliable

• Produces no greenhouse gases or CO₂ during operation

• No fuel costs

• Can also be used directly for heating

Disadvantages of geothermal power:

• Not many suitable locations

• Can release methane (a greenhouse gas) during the extraction process

Solar

Advantages of solar power:

• Produces no greenhouse gases or pollution during operation

• Useful where there is no mains electricity supply (e.g. remote areas)

Disadvantages of solar power:

• Unreliable — only generates electricity when the Sun is shining

• Each solar cell only produces a small amount of electricity, so many cells are needed

• High initial cost of solar panels