1.14 - Fossil Fuels & Nuclear Energy

Fossil fuels and nuclear fuel are non-renewable

• Non-renewable energy resources are used up far faster than nature can replace them, so they'll eventually run out.
• There are two kinds: fossil fuels and nuclear fuel.

Fossil fuels

• The three main fossil fuels are coal, oil, and (natural) gas.
• They formed underground over millions of years from the buried remains of living things.
• They're burnt to release the energy they hold.

Nuclear fuels

• The nuclear fuels are uranium and plutonium.
• Their energy is released by a nuclear reaction rather than by burning.

Shared features

• They're reliable sources of energy.
• They'll all run out one day.
• They damage the environment when used.

Non-renewables are reliable but are running out

Advantages

• Reliable - There's enough fuel to meet current demand, and power stations can keep fuel in stock.
• Respond to demand - Gas power stations can change their output quickly by changing how much fuel is burnt. Coal and nuclear power stations are much slower.
• Large scale - They produce large amounts of energy using relatively little land.
• Cost - Fossil fuels are fairly cheap to extract, and fossil fuel power stations are relatively cheap to build and run. Nuclear fuel is also relatively cheap.

Drawbacks

• Running out - Fossil fuels are finite and will eventually run out.
• Nuclear costs - Nuclear power stations are expensive to build and very expensive to decommission (shut down and make safe).
• Start-up time - Nuclear stations take the longest to start up, while natural gas stations take the shortest.

Factors used to compare energy resources

• Economic cost (building, running, and decommissioning)
• Environmental impact
• Sustainability of the resource
• Start-up time
• Generating capacity (maximum power output)

Non-renewables create environmental problems

Burning fossil fuels

• Carbon dioxide (CO₂) - Coal, oil, and gas all release CO₂ when burnt. This increases the greenhouse effect and contributes to global warming. Coal releases the most CO₂ per unit of electricity, and natural gas the least.
• Sulfur dioxide - Burning coal and oil releases sulfur dioxide, which causes acid rain that harms trees, soils, and aquatic ecosystems.
• Spoiled landscape - Mining fossil fuels (especially open-cast coal mining) and building power stations spoil natural landscapes.
• Oil spills - Transporting and drilling for oil can cause spills that seriously harm wildlife and marine environments.

The carbon footprint of an energy resource measures the total amount of greenhouse gases released over its entire lifetime, including building and decommissioning the power station.

Nuclear power

• Nuclear fuel does not release CO₂ or sulfur dioxide during electricity generation.
• It produces radioactive waste, which remains hazardous for thousands of years and is difficult to store safely.
• Mining, processing, and transporting nuclear fuel releases CO₂ because these processes rely on fossil fuels.
• There's a risk of radioactive material being released during a major accident.