Coal is a fossil fuel and has been generating electricity in Great Britain since the industrial revolution. But the decarbonisation of the grid will see it phased out by the end of 2024.
In 1882, Thomas Edison’s Holborn Viaduct coal plant started generating electricity for public use. It was the first power station of its kind, burning enough coal to provide energy to light 1,000 lamps in the City of London.
The principle of how coal generates electricity is fundamentally the same as in Edison’s day, and similar to other thermal power stations like gas: the coal is burned, heating water to create steam, which spins a turbine to produce electricity.
Throughout the late nineteenth and twentieth centuries, this is how much of Britain’s power was produced. Coal generation peaked in the early nineties, making up over 60% of the mix before the ‘dash for gas’ heralded its decline.
What happens when coal is burned?
When coal is burned, it reacts with oxygen in the air and all the stored solar energy is turned into thermal energy and released as heat. However, this chemical reaction also produces carbon dioxide and methane, greenhouse gases which are harmful to the environment. So when we talk about decarbonising our electricity system, it means we stop using fuel sources that emit carbon into the atmosphere.
Is coal still used in Britain?
Coal used to generate a third of Britain’s power, but since the electricity system has decarbonised, its contribution to the country’s power mix has reduced rapidly by a whopping 97% since 2012.
For the last two years only 1.6% of electricity in Britain was generated by coal, and we’ve seen significant periods of coal-free electricity generation, including a record 68 day run, in 2020.
Coal is still part of the generation mix in Britain today, and while it’s due to be phased out, it’s likely to continue contributing small amounts to the mix in the meantime.
The heavy spinning turbines in coal and gas generators – whose rotating speed syncs with the grid’s frequency – bring important stabilising properties like inertia to the electricity system.
That means our control room will have less and less need to call on thermal generation like coal through the balancing mechanism, bringing us closer and closer to being able to operate the system with zero carbon.
You can track the decarbonisation of Britain’s electricity system – and the declining role of coal in the power mix – via our live carbon intensity dashboard.