Energy storage: UK puts faith in tech to harness the renewable revolution
The worst pandemic in nearly a century, Russia’s invasion of Ukraine, and a global economic downturn have caused historic volatility across the energy sector.
Such a spiral of dramatic events has made it difficult to keep track of stories that don’t flare up in 24-hour news cycles or trend easily on Twitter, such as renewables’ steady rise in the UK’s energy mix.
This was confirmed only last week by the National Grid’s electricity system operator – which revealed wind power provided 21GW of generation for the first time ever over a half-hour window on 10 January.
Meanwhile, its report on energy usage in 2022 revealed that low carbon electricity sources such as solar, wind and hydrogen alongside nuclear generated over 50 per cent of the UK’s energy in February, May, October, November and December last year.
These figures are highly encouraging for the government which unveiled its energy security strategy following Russia’s invasion of Ukraine.
Its ambitious targets include ramping up solar power from 14GW to 70GW by 2035 and boosting offshore wind from 11GW of assets to 50GW by the end of the decade – alongside an ambition to reach 10GW of hydrogen over the same time period.
The challenge now for the government is harnessing that potential rapid expansion – making the possibility of storing that energy to meet the UK’s future needs increasingly vital as the country shifts away from fossil fuels.
Battery storage: The plusses and negatives
The European Union and the UK has staved off blackouts this winter with the aid of vast top-ups of liquefied natural gas – chiefly from the US – with supplies stored in containers for weeks at a time on the continent.
By contrast, the current timeframe for lithium-ion batteries storing renewable energy is only a matter of hours.
Meanwhile mechanical options such as pumped hydrogen and liquid air have clocked in around a day of storage, with the pumped facility in Cruachan, Scotland, securing the longest duration for output domestically at 22 hours.
Adam Bell, head of policy at Stonehaven and former head of energy at BEIS, was optimistic these challenges would be resolved.
In his view, electrical stores like lithium and vanadium flow batteries could provide more short-term charging options such as for EVs, while longer-term storage needs would be provided potentially by chemical stores where energy was stored as molecules, such as hydrogen.
He expected both continued innovation in the sector and a wide array of energy sources to be available to meet the UK’s energy needs alongside – with nuclear in the mix as a baseload alternative.
Bell said: “Each have a different role to play – electrical stores tend to be optimal for intra-day solutions, mechanical for intra-week and chemical for intra-seasons. Getting the mix of these assets right is a challenge for both government and the system operator [National Grid], who will need to design the right markets to bring forward the right mix of assets at the right time.”
However, James Baden, founder and director of clean energy storage specialist Zenobe Energy, believed that the renewables sector needed to recognise gas was likely to have a continued role in the supply mix for the next two decades.
He said: “Gas is going to be part of the mix for the next 15 years or so, until we’ve got sustainable long term storage solutions. I can see gas being on the network up to 2040.”
In his view the West would have to maintain gas reserves not just for the renewable transition but for future emergency situations after Russia’s invasion of Ukraine.
“Everybody became somewhat complacent, having had no war in Europe for 70-80 years,” he concluded.
Renewable sector has faith in breakthroughs
Octopus Energy has calculated that there is just over 3GW of lithium-ion battery storage installed nationwide, with a further 6GW in development and another 30GW in the planning stages.
Devrim Celal, chief executive of the energy giant’s management platform Kraken Flex, was optimistic further developments of interconnectors could help boost the UK’s energy supplies in times of potential shortages – with the country connected to around 6GW of electricity capacity from France, Netherlands, Belgium, Northern Ireland and Republic of Ireland.
While he recognised long term storage solutions would eventually be needed, Celal argued that “it’s not a problem to solve today” and that there will be “technologies in place to solve it, when the time comes”.
He compared solutions in the green energy sector to the intense innovation window for the Covid-19 vaccines.
Celal said: “It took us a year to come up with a vaccine that would have taken decades before. So, if we put our focus and energy into it – I don’t think the problem we’re trying to solve is a major one. I think we should double down on renewables and double down on interconnectors.”
One example of innovation in the energy sector is Zenobe’s battery storage plans to deal with the embarrassing situation where National Grid has to pay wind and solar operators to reduce generation during periods of peak sun and wind power, while also paying gas operators to come online.
For the first 11 months of 2022, National Grid forked out £1.34bn constraining energy supplies – including £122m on wind power – to prevent the grid being overwhelmed.
In the past month, £82m was spent turning off wind turbines – as first reported by Kona Energy – even amid periods of record generation.
Zenobe has commercial contracts to develop large 200-300 MW battery facilities which would store power for multiple hours every day, and would be available for the grid during surges – meaning National Grid would no longer have to turn to fossil fuels to deal with shortcomings in renewable power.
Basden explained: “What happens is that because of the batteries, National Grid knows that the batteries can kick in very fast – faster than the breakers, around 100 milliseconds or less. So, that power actually goes on to the grid network, so that the wind is not curtailed off and the gas heaters don’t come on.
It took us a year to come up with a vaccine that would have taken decades before. So, if we put our focus and energy into it – I don’t think the problem we’re trying to solve is a major one.
Devrim Celal, chief executive of Octopus’ management platform, Kraken Flex
“As a result, not only is that a lot cheaper, but it has environmental benefits. We’re the first to do that at a large scale.”
Overall, the renewable sector remains bullish about its prospects, reflected in the outlook of Barnaby Wharton, director of future electricity systems at industry body Renewable UK,
He recognised the UK “needed every kind of tool in the box” including long-term storage, but believed the start point in terms of technology was already there – with batteries, hydrogen, and offshore wind.
He said: “It’s about how we deploy them: How do we get the cost down, to make sure that they are competitive and good for consumers?”