Britain will need gas plants as ‘back-up’ for wind in 2030, says grid operator

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Britain’s fleet of gas-fired power plants will need to stay online as back-up in 2030 even if the government hits its target of decarbonising the power system by then, according to official modelling published on Tuesday. 

Gas plants currently account for about a third of Britain’s power requirements. While this will fall to less than 5 per cent in 2030, the same capacity of plants as today will be required as a “strategic reserve” for windless days, the National Energy System Operator said on Tuesday. 

Its modelling is part of a wide-ranging study by NESO that considers whether and how the new Labour government can reach its flagship manifesto pledge of a clean power system in 2030. 

It concludes that “urgent action” is needed to speed up the development of new wind turbines, solar panels and pylons, while consumers will also need to be far more flexible about when they use electricity. 

The report finds that the overhaul requires annual investment of more than £40bn, with nearly 2,700 miles of offshore electricity cables and 620 miles of onshore cables to be built.

It concludes the overall costs of running the system in 2030 “should not increase for a clean power system”.

But it dodges the question of whether household bills will fall, something that had been promised by energy secretary Ed Miliband during the election campaign. NESO said too much depends on how the government chooses to fund its policy costs.  

Many of these are currently added to electricity bills, but several campaigners and industry executives say they should be moved on to gas bills or funded through general taxation instead. 

“How costs flow through to prices, and ultimately bills, will depend on policy design,” said the NESO report.

“We do not attempt to estimate an actual electricity bill given the heavy dependence on policy choices,” it said.

In response, Miliband said the report was “conclusive proof that the government’s clean energy superpower mission is the right choice for the country”. The government is “determined to ensure the significant reforms to planning and grid we need,” he added. 

The government now faces significant decisions about how to fund support for the overhaul, and how robust it is prepared to be in overriding communities’ objections to new pylons nearby.

“Given the scale of the challenge it may be appropriate to aim high and unblock barriers across all areas,” NESO said.

Low carbon sources such as wind, solar and nuclear power supplied 51 per cent of Britain’s electricity in 2023, with gas supplying 32 per cent over the year, with the figure rising significantly on windless days. 

Under NESO’s modelling, the role of gas will fall to less than 5 per cent in 2030. However the same capacity of power plants as today will still be needed to step in on windless days, when its contribution would be far higher.

This is likely to be supplied mostly by the existing fleet in 2030, although over time gas-fired power stations may be fitted with carbon capture technology or replaced by models running on hydrogen. 

Gas-fired power plants currently receive payments to be on standby; these are expected to balloon from about £1bn this year to about £4bn in 2029-30, according to forecasts published last week by the Office for Budget Responsibility.

Under NESO’s modelling, Britain’s offshore wind capacity would also have to jump from 15GW to 43-50GW by 2030, while onshore wind would have to rise from 14GW to 27GW and solar would need to treble from 15GW to 47GW. 

The country would maintain up to 4.1GW of nuclear power in 2030, partly by keeping open Sizewell B and by extending the life of at least one other existing nuclear power station. 

Crucially there would also have to be a big jump in the use of “demand flexibility” that sees both households and companies encouraged to use more energy when there is more availability. 

One government figure said there would need to be an information drive by both the state and by energy companies to encourage more flexible energy use: “We will have to do more selling to people the benefits and upsides of this.”