Flexibility on the front line
Ukraine is showing the power of flex to make energy systems more resilient. What are the lessons for the UK? We went to the experts, including the flexibility commissioner, to find out.
By Ben Hargreaves, head of content
Flexibility on the front line
Ukraine is showing the power of flex to make energy systems more resilient. What are the lessons for the UK? We went to the experts, including the UK’s flexibility commissioner, to find out.
By Ben Hargreaves, head of content
As winter looms in Ukraine, Russia is once again proving that targeting energy generation is a weapon of war.
But could scores of new distributed power resources on the Ukrainian grid be the country’s best defence?
The data shows that Ukraine is rapidly growing its decentralised energy assets. The beleaguered country added 1.1GW of new solar power capacity in the first half of the year alone, a figure that could reach 2GW by the end of 2026, according to the Solar Energy Association of Ukraine (SEAU).
Vladyslav Sokolovskyi, chairman of SEAU, emphasises that distributed generation and battery energy storage systems have become an important component of Ukraine’s energy security, supplying electricity to businesses, households and critical infrastructure during the war.
Approximately 80% of new installations are expected to be projects with a capacity of less than 1MW, primarily intended for self-consumption. According to SEAU data, Ukraine also added approximately 2.9GWh of energy storage capacity in 2025. Additions in the first half of 2026 are estimated at 1.6–1.9GWh, with around 3.2GWh expected for the full year.
Necessity is the mother of invention in Ukraine as the country battles to keep the lights on this winter. But here in the UK, flexibility commissioner Cathy McClay says distributed generation is also becoming a vital source of power. McClay, who is also managing director of National Grid DSO, explains that peak demand on the network is 13GW, but peak generation is now at 15GW.
“So, it’s not really a distribution system anymore, is it?" she says. "I’ve got as much generation as demand – and a lot of that’s solar. By 2030 we expect an extra 10GW of generation, and by 2035 another 10GW.
Energy storage capacity added in Ukraine in 2025
Target for additional storage capacity this year
“A lot of this smaller flexibility can be used to meet local demand.”
McClay would like the energy system to embrace this opportunity now, before the need is critical. She points out that she spent the latter half of the 2010s at the system operator and understands the attraction of maintaining the status quo: “I ran the markets there between 2015 and 2019. I understand that when you’re in the control room and you must keep the lights on, you use what you know.
“But we need to start using [decentralised energy resources] more, especially when it’s cheaper. We should learn how to use them. Once gas is going off the system, we need to know how to use batteries properly.”
Flexibility of this type will help to decarbonise the economy. It also has the potential to save consumers money and has implications for energy security.
“We’ve seen Ukraine experience massive power interruptions since it was invaded in 2022, but the main reason it has been able to maintain any kind of security of supply is a decentralised system,” says Sarah Honan, head of demand at the ADE (formerly the Association for Decentralised Energy). “Decentralise. Make everything its own little power plant and vulnerabilities start to lessen.”
Are lower bills down the road?
Power plants aren’t the only things that are vulnerable. The role of flexibility in the lives of consumers – and the potential benefits in terms of cutting bills – were important elements of the update to the Clean Flexibility Roadmap issued in July. In fact, consumer-led flexibility (CLF) gets the longest chapter in the update.
Experts point out that there is vast untapped potential for people to shift their electricity use away from peak times, or to use more when power is cheap and plentiful, using automation. In theory, participants get lower bills, and everyone benefits from lower system costs. McClay points out that the recent eye-watering costs of balancing the grid in September could be a thing of the past if the potential of CLF were fully exploited. “If you take constraint costs… there are two things going on,” she says. “One is paying the generators north of the constraint to turn down, and the other is paying the generators south of the constraint to turn up.
“Flex can help with tackling both of those. And, interestingly, two-thirds of the cost of constraints is turning the generators up south of the border.”
McClay points out that decentralised, low-carbon generation is already playing a major role at National Grid. There are now more than 400,000 assets registered in McClay’s flex market. She says demand turn-down by consumers is relatively proven: “Where clean flex is already competitive is in demand turn-down. So why shouldn’t we tackle turning down demand, rather than turning up generation, to solve constraints?”
Demand turn-up also represents a huge opportunity to avoid curtailment costs. “It’s a really good product for poorer homes,” McClay says. “People say you don’t need heating in the summer, so turn-up doesn’t work – but there is a lot of social housing that has electric boilers for water, or immersion heaters.
Number of flex assets registered in the flex market run by National Grid DSO
“So we’re paying households to use them when the sun is out.”
All of which helps the DSO to create a decarbonised system. “There have only been three days since April 2025 where we have had any carbon content in our market, which I think is amazing,” says McClay proudly. In fact, the system is actually carbon negative overall. “That’s because we use clean turn-up to keep generation on. We’ve dispatched 8.9GWh already this year and the national level is bigger. But we’re showing this stuff is reliable.”
Aggregation of energy sources is an important factor in enabling that reliability. To illustrate the point, McClay recalls her time as director of flexibility at ENOWA, part of NEOM in Saudi Arabia: “We quickly worked out that trying to manage all these flexible assets as individual assets just doesn’t scale – there’s far too much information. That’s where aggregation really comes into its own. If you’ve got a bunch of EVs, each individual EV won’t do precisely what you want in the balancing mechanism. But if you aggregate them into a virtual unit, and you have enough, you can get them doing the right thing.”
With networks making use of flex already, there is now a need for the government to sharpen its focus, says Tom Luff, who leads the policy and business model innovation team at the Energy Systems Catapult: “We need stronger policies to drive electrification, more ambition on market reform, and better coordination from national markets right down to individual homes.”
It is driving electrification that will bring down bills, he says: “The overall government strategy depends massively on growing electricity demand to help spread the costs of new infrastructure. I’d say that growth isn’t happening as fast as it needs to.”
Hurdling the barriers to a flexible future
Honan, who is working closely with McClay to deliver on the goals of the Clean Flexibility Roadmap, agrees there have been blockers to quicker up-take of flex.
Ironically, one of them was not asking for money. “Because consumer-led flex… wasn’t asking for a big subsidy or a bespoke support mechanism, it often fell through the cracks,” she says, adding that technologies such as carbon capture, utilisation and storage (CCUS) and hydrogen have received a disproportionate amount of attention given that the Clean Power Action Plan called for a five-fold increase in flexibility. “The amount of consumer-led flex we think we need by 2030 absolutely dwarfs what we need from both those technologies, but it doesn’t get as much attention,” she adds.
“What we always say is that, unlike other sectors in the clean power revolution, we are not asking for a big investment of money. We’re asking for an investment of time, coordination and consistency – and often it’s harder to get those things than it is to get a cheque.”
Nonetheless, progress is being made, Honan says. “If we could spend less time battling what we would consider bad ideas, we could spend a lot more time progressing good ones,” she argues. “Getting Ofgem to change the approach it was taking to ED3 from ‘build, build, build’, to ‘build and flex’ was super-welcome – but that took a lot of time.” Despite this shift in emphasis, there is still a “risk of overbuilding network infrastructure”, she adds.
Meanwhile, consumer-led flexibility would benefit from price signals in specific locations and at differing times, says Luff: “We need to think about how you ration the use of local networks so you spread the load across them as efficiently as possible. And we need to do it in a way that passes the value back to the consumer.”
He says we need signals to be locationally accurate: “Otherwise you end up with a situation where you’ve got lots of wind coming in from the wind farms in Scotland that can’t get across the country because of grid constraints. But the signal is: wind is on, so electricity is cheaper. People in the south then plug in their EVs because electricity is cheaper, but because the electricity can’t get down there, [NESO is] having to pay to switch on gas-plant backup generation.”
This is what happened when NESO recently made headlines by spending £50 million in a single day on balancing the system, says Luff: ”I think that’s a record for one day. Unless we get those signals right, those costs are only going in one direction, which is up.
“With locational pricing, gas would only set the price where it’s actually needed, rather than across the whole country, allowing areas with abundant renewables to benefit from cheaper electricity. My view is that the only way you can delink from gas is through a more locationally based wholesale market.
“Next year will be a pivotal one for flexibility; it needs to be a decision year. If the system isn’t providing the signals that are needed and constraint costs are going up, then government needs to revisit the decision on locational pricing.”
But McClay cautions that we should not give consumers too much to do: “There is the big question of implicit versus explicit flexibility. The more we can get it just doing the right thing itself, without having to intervene, the better.”
For instance, overexposure to price signals might mean people use flexibility services in a way that’s not helpful for them, because it isn’t automated, or they don’t fully understand what they’re doing. Honan agrees: “Flexibility is about automated processes, it's like the analogy of the swan on the water: the legs are going underneath, but it’s calm and serene above the surface.”
“There’s a big debate about how much we should expose people to prices, versus how much we should look after them,” says McClay. “If we genuinely want demand to do the right things for the network, it has to be exposed to the price. Then people have to be supported to react in the right way to the price, which means more automation.
“Then, of course, you’ve got the issue of trust. Is my supplier really the right person to tell me what tariff I should be on?
“That’s something we really need to think about as an industry.”
She agrees with Luff that electricity prices need to be decoupled from gas as soon as possible, however. “The area I’ve been pushing very hard, which is in the flexibility roadmap, is decoupling the price of gas from the price of electricity,” she says.
“The way to do that is to use gas less. It’s as simple as that.”
“There’s a big debate about how much we should expose people to prices, versus how much we should look after them.”
Cathy McClay, flexibility commissioner and managing director of National Grid DSO
