Power Generation
Coal and nuclear power stations generate electricity in the same way; fuel is burned to heat water, turning it into steam. The steam passes through a turbine that drives a generator, making electricity. The only significant difference between different means of power generation is the choice of fuel.
Coal
Until the 1960s, the UK was one of the world’s largest coal producers, and by far its largest exporter. Coal production peaked at nearly 300 million tonnes a year in the early 20th century but, by 1999, had fallen to 37 million tonnes.
Estimates of the amount of coal remaining in the UK range from 800 million to 190 billion tonnes - depending on how you define 'recoverable'.
The steep decline in coal production is caused largely by economic factors, such as competition from other fuels like oil, nuclear and, most recently, natural gas. But coal also has a very high carbon content, which means it contributes disproportionately to greenhouse gas emissions.
New technology is being developed to capture the carbon (a process called 'sequestration'), but renewable energy sources are widely seen as a more sustainable long-term alternative.
However, coal remains the biggest single source of fuel for Scotland's power generating industry, accounting for 3.5 GW - over a quarter of Scotland's power generating capacity.
Nuclear power
Compared with fossil fuels, nuclear power produces very little pollution and virtually no greenhouse gases. While these qualities make it an attractive option to reduce greenhouse gas emissions, there is significant public resistance to nuclear power.
This is because the waste that is produced is highly radioactive and toxic, and remains so for a very long time - tens of thousands of years, in some cases. There is, in the UK at least, no clear consensus on how we should manage this waste.
Worldwide, France is the most reliant on nuclear power. Almost three-quarters of France's electricity is generated in nuclear power stations. The UK generates about 25 per cent of its power in over 30 nuclear power stations.
In Scotland there are three nuclear power sites: Torness in East Lothian, Hunterston in Ayrshire and Dounreay in Caithness. Dounreay opened in 1954 to develop the UK's fast nuclear reactor programme. However, it proved uneconomic and the programme has now stopped.
Since then, the emphasis at Dounreay has been on finding a safe and environmentally responsible way to decommission the site, which will take around 100 years and presents significant opportunities in itself.
Find out more about decommissioning opportunities in the power generation sector