Experts on long duration energy storage (LDES) are split on the necessary target needed to deliver the UK’s decarbonisation goal.
While some experts have urged the government to set a long-term target of up to 100TWh, others have suggested that a smaller “no regrets” target should be set to “get the ball rolling” on LDES.
However, officials from the Department for Energy Security and Net Zero (DESNZ) refused to be pushed on the possible size of a target, when repeatedly asked to do so during the House of Lords Science and Technology Committee’s inquiry into LDES.
DESNZ chief scientific advisor Paul Monks said: “We are all in agreement that we will need more storage and we will need a range of technologies. However, setting specific amounts is very sensitive when talking about future energy mix and future demand.”
The UK currently has 4.9GW of energy storage installed. Pumped hydro storage makes up the majority of this capacity at 2.8GW whereas battery energy storage systems (BESS) account for around 2.1GW. However, there is a combined pipeline of storage developments of 34.5GW.
As part of its plans to decarbonise the grid by 2035, the government has previously announced that it looking to bring in policy specifically around LDES by the end of next year.
DESNZ director of energy systems and networks Emily Bourne added that a proposed policy approach and consultation will be published by the end of this year.
In response, committee chair Baroness Brown said that the government’s proposal was “cutting it fine”, given lengthy planning processes associated with energy storage projects. She added: “Shouldn’t we be kicking off now with no regret schemes?”
Bourne said that at this stage the government’s focus “is on delivering the type of mechanisms needed to fund the various technologies needed for energy storage”, rather than setting a capacity target.
She added that the government’s minded-to position on a funding mechanism would be set out alongside the consultation at the end of the year. Bourne said that while discussions are still ongoing about the type of mechanism that will be developed, she confirmed that most respondents to an earlier consultation backed a “cap and floor” style funding mechanism similar to that used to fund the development of interconnectors.
Also speaking at the inquiry, representatives from the Committee on Climate Change renewed their calls for the government to identify “a low or no regret” target to be set sooner rather than later.
It is a stance that was supported by Michael Liebreich, chair and chief executive at Liebreich Associates. Giving evidence to the inquiry, Liebreich suggested that a target as low as 10TWh “would be a perfectly good policy outcome for this year and the next few years to carry us forward”.
Liebreich said that it would “give us some idea of the scale that needs to be built in the system to really start pushing policy and technology choices”.
He added: “This stuff will take so long to build that there are no regrets to building some number of terawatt hours and starting now, because we will need them. So whether the number ends up having to be 10, 20, 30 terawatt hours by 2050 we will not regret starting now.”
On the other side of the argument, Sir Chris Llewellyn Smith has supported a larger, longer-term target of 100TWh of LDES by 2050.
In a recent report for the Royal Society, Large scale electricity storage, Smith said that “the need for long-term storage has been seriously underestimated”.
Speaking to Utility Week, Julia Souder, chair of the Global Renewables Alliance and chief executive of the Long Duration Energy Storage Council, said she too supported a larger target.
“I think it’s great to see the initiative and the desire to push forward, but there’s always more work to do because the scale is enormous of what we need to reach. So I think a larger LDES target would be really strong,” she said.
“We have a lot of work to do, so I think increasing the targets where possible is a good thing. But that has to come with adding more incentives in to ensure that the targets are supported with subsidies. Incentives are important, mandates are important.
“If you provide the incentives it gives the right market signals and that’s really powerful and important. It’s a case of building on existing tool sets. It’s not reinventing the wheel.”