Britain’s power grid bets on flywheels to maintain the lights on
By Akshata KAPOOR
Liverpool (AFP) Aug 31, 2025
Britain’s power operator is betting on an age-old expertise to future-proof its grid, as the facility vegetation that historically helped stabilise it are closed and changed by renewable power methods.
Spinning steel gadgets often called flywheels have for hundreds of years been used to supply inertia — resistance to sudden adjustments in movement — to numerous machines, from a potter’s wheel to the steam engine.
Grid operators at the moment are seeking to the expertise so as to add inertia to renewable-heavy electrical energy methods to stop blackouts just like the one which hit Spain and Portugal this yr.
In an electrical energy grid, inertia is usually offered by massive spinning turbines present in coal-fired and gasoline energy vegetation, serving to keep a gentle frequency by smoothing fluctuations in provide and demand.
However renewable power sources like photo voltaic and wind energy do not add inertia to the grid, and often can not assist with different points, resembling voltage management.
Flywheels can mimic the rotational inertia of energy plant turbines, spinning faster or slower to answer fluctuations.
With out rotating generators, “the system is extra vulnerable to fluctuations than it might be in any other case”, defined David Brayshaw, a professor of local weather science on the College of Studying in England.
“As we get to ever greater ranges of renewables, we’ll have to consider this extra rigorously,” Brayshaw instructed AFP.
– Flywheels and batteries –
The Iberian Peninsula, which is powered by a excessive share of renewables, went darkish on April 28 after its grid was unable to soak up a sudden surge in voltage and deviations in frequency.
Spain’s authorities has since pointed fingers at standard energy vegetation for failing to regulate voltage ranges.
It may function a wake-up name just like a 2019 outage which plunged components of Britain into darkness following a drop in grid frequency.
That blackout prompted UK power operator NESO to launch what it known as a “world-first” program to contract grid-stabilising tasks.
Flywheels and batteries can add artificial inertia to the grid, however engineering professor Keith Pullen says metal flywheels could be cheaper and sturdy than lithium-ion batteries.
“I am not saying that flywheels are the one expertise, however they might be a really, crucial one,” mentioned Pullen, a professor at Metropolis St George’s, College of London and director of flywheel startup Levistor.
Within the coming years, Pullen warned the grid can even turn into extra unstable resulting from better, however spikier demand.
With electrical vehicles, warmth pumps and energy-guzzling information centres being hooked onto the grid, “we could have extra shock hundreds… which the flywheel smooths out”.
– Carbon-free inertia –
Norwegian firm Statkraft’s “Greener Grid Park” in Liverpool was one of many tasks contracted by NESO to maintain the lights on.
Operational since 2023, it’s a stone’s throw from a former coal-fired energy station website which loomed over the northern English metropolis for many of the twentieth century.
However now, as an alternative of steam generators, two large flywheels weighing 40 tons (40,000 kilograms) every whirr on the Statkraft website, which provides one p.c of the inertia for the grid wanted in England, Scotland and Wales.
Every flywheel is hooked up to a synchronous compensator, a spinning machine that additional boosts inertia and offers voltage management providers within the Liverpool area.
“We’re offering that inertia with out burning any fossil fuels, with out creating any carbon emissions,” mentioned Man Nicholson, Statkraft’s zero-carbon grid options head.
Based on NESO, 11 different comparable synchronous compensator and flywheel tasks had been operational in Britain as of 2023, with a number of extra contracted.
– ‘Not quick sufficient’ –
The federal government is “working carefully with our trade companions who’re creating world-leading expertise, together with flywheels, static and synchronous compensators, as we overhaul the power system”, a Division for Power Safety and Web Zero spokesperson instructed AFP.
However, “we aren’t constructing them quick sufficient to decarbonise the grid”, warned Nicholson.
Britain goals to energy the grid with clear power 95 p.c of the time by 2030, earlier than fully switching to renewables within the subsequent decade.
“In the mean time… we will not even do it for one hour,” mentioned Nicholson.
Even when there’s adequate photo voltaic and wind power being generated, “we nonetheless must run gasoline generators to maintain the grid secure”, he defined.
Nonetheless, Britain and neighbouring Eire appear to be forward of the curve in procuring expertise to stabilise renewable-heavy grids.
“In GB and Eire, the system operators are main by contracting these providers,” Nicholson mentioned. “On the continent, there hasn’t been the identical drive for that.”
“I believe these items are pushed by occasions. So, the Spanish blackout will drive change.”
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