Great Britain has smashed the record for generating electricity without coal for the second time in a month. But this unprecedented coal-free fortnight doesn't mean that renewables are filling in the gap
In 1882, the Edison Electric Light Company opened the world’s first commercial coal-fired power station at an unlikely central London address. The facility at 57 Holborn Viaduct burnt the fossil fuel to drive a steam turbine that powered some of the first electric street lights nearby, as well as private residences.
For the next century, the UK was reliant on coal to light its streets and heat its homes. As recently as six years ago, burning the black stuff provided 40 per cent of the UK’s electricity needs. But that has been changing, and the country is on an unprecedented streak for continuous energy generation without coal.
At around 2PM on May 1, Great Britain stopped burning coal to generate power. It smashed the previous record of 90 hours, set in April, during the early May long weekend, and at around 2PM on Wednesday, May 8, the country reached the landmark of seven days without using coal. At 3.12PM on Friday, May 31, it smashed the record again, going an entire fortnight without burning any coal for electricity. Northern Ireland is powered by a grid shared with the Republic of Ireland, so wasn't part of this record-setting fortnight.
“As more and more renewables come onto the system, we’re seeing things progress at an astonishing rate," says Fintan Slye, director of National Grid Electricity System Operator (NGESO). "We also broke our solar record for GB this month – with one day seeing over a quarter of the country powered by the sun."
A longer than usual spell of sunny and windy weather has played a part, but this is the fruit of a long-term plan to edge the UK away from coal, and towards renewables and natural gas. “As more and more renewables come onto our energy system, coal-free runs like this are going to increasingly seem like the ‘new normal,’ said Julian Leslie, head of national control at NGESO, when the record reached seven days earlier this month. “We believe that by 2025 we will be able to fully operate Great Britain’s electricity system with zero carbon.”
Climate change activist Greta Thunberg was critical of Britain’s record on climate change in a speech to Parliament last month, but the country has been a pioneer of onshore and offshore wind power, which has picked up some of the slack lost from coal.
The UK has more installed offshore wind power than any other country, and the cost of offshore wind has fallen by half since 2015 – according to RenewableUK, it’s now cheaper than building new gas and nuclear power stations. Offshore wind alone can provide enough power for 4.5 million homes, and there are huge projects under construction off the coasts of East Anglia and Scotland.
“Wind has become a mainstream power source for the UK, providing up to 35 per cent of our electricity over the weekend,” says RenewableUK’s deputy chief executive Emma Pinchbeck. “Solar was generating up to 21 per cent, so renewables overall are playing a leading role in our energy mix.”
But that’s only part of the story. On Saturday, May 4, for example, wind accounted for more than a quarter of the country’s power needs, with a further quarter being fulfilled by nuclear, and another by gas. But when the wind dropped, the shortfall was not filled by other forms of renewable energy.
“This is not totally a coal to renewables shift,” says Dr Grant Wilson, who conducts research into energy systems at the University of Birmingham. We’ve largely replaced one fossil fuel with another – instead of burning coal, we’re using natural gas.
The demise of coal was underway before current fears of climate change, says Dr Rob Gross, director of the Centre for Energy Policy and Technology at Imperial College and member of the UK Energy Research Centre. “The oldest coal-fired power stations were coming towards the end of their lives,” he explains. “They weren’t compliant with EU regulations for acid rain and so it didn’t make sense to upgrade them.”
Renewables subsidies from successive governments have driven down the cost of installing solar and wind, which is now cost competitive with other forms of energy generation. But the biggest nail in coal’s coffin has been carbon pricing, which has made coal more expensive than natural gas.
Gas emits about half as much carbon as coal per kWh of electricity it generates, and the UK is uniquely well-positioned to take advantage of it, thanks in part to the much-maligned privatisation of the energy industry. In the late 1980s and early 1990s, the UK electricity supply was split up into regional suppliers.
At the time, natural gas was mainly used for heating, and was not considered a viable source of electricity - but a couple of the new energy suppliers took a gamble on it. This sparked what’s known as the ‘dash for gas’ as all the other companies embarked on their own gas-fired power projects, and saw coal’s share of the grid fall from 66 per cent to 34 per cent between 1991 and 1999. When the old coal-fired power stations began to be phased out, the UK was almost unique in having a replacement ready to go.
As coal-fired power stations have gone and renewable energy has come online, those running the electricity infrastructure have been forced to adapt. “It’s been a lot of work and effort over a number of years,” says Leslie. At NGESO work is ongoing to add flexibility to the grid, with voltage control circuits and other technologies that enable intermittent renewables to be used as if they were continuous coal-fired power plants. “We’ve always needed flexibility, but in the past we’ve had the benefit of really significant stores of energy,” says Wilson. “As we move away from these fuels we need to think about how we structure the tools at our disposal.”
There are potential problems on the horizon. The difficulty in getting new nuclear power stations off the ground could throw a spanner in the works. The UK’s eight nuclear power stations provide around 20 per cent of its energy, but seven of them are due to be decommissioned before 2030, with only Hinkley Point C coming online to replace them. “If we don’t replace these nuclear power stations with low carbon capacity - new nuclear or renewables – we would expect to see emissions rise,” says Gross.
Filling that hole will mean accelerating the uptake of renewables even further, and finding ways to balance their intermittent nature with new energy storage technologies. Over the next six years, NGESO will be trialling a host of new technologies, from flywheels to supercapacitors, that can add more flexibility to the grid and support more coal-free days.
“The pace of change is phenomenal,” says Leslie. “We’ve proven we can run without coal, and now we need to do the same for gas.” It’s difficult, but it will be worth it. “The transformation of how we get the energy to heat our homes and power our work is a massive change, but the advantages it brings in terms of green energy far outweigh any challenges.”
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