Solar power threatens to overwhelm electricity grid
Energy chiefs are drawing up plans to stop the electricity grid from being overwhelmed by solar power this summer.
The National Energy System Operator (Neso) said it will be forced to use “more tools, more often” to keep power networks stable when sunny weather causes surges in energy generation.
This will include paying households and factories to consume excess power for the first time, as well as potentially issuing unprecedented orders to switch off large power stations.
The warning was made as Rachel Reeves travelled to Washington, where she will urge a gathering of world leaders to “follow her plan” to combat the energy crisis caused by the conflict in the Middle East.
At the International Monetary Fund summit, the Chancellor will call for “collective action” while urging countries to embrace net zero to boost energy security.
She will also pledge to “do all in her power to keep costs down for the British public”, warning against “knee-jerk decisions that are unaffordable and deepen economic pain”.
As Donald Trump threatened to blockade Iranian vessels attempting to pass through the Strait of Hormuz on Monday, oil traders warned that the price of crude now risks hitting $150 per barrel – up from around $100 today.
Ministers said their priority was to support diplomatic efforts to reopen the Strait, but that they were drawing up “contingencies” to ensure crucial supplies of fuel such as red diesel for farmers.
In its summer outlook, published on Tuesday, Neso said there were currently no concerns about the security of electricity supplies this summer, but that war in Iran would push prices higher because of Britain’s dependence on gas.
However, it warned that gluts of solar power and “low demand” periods were making the grid more difficult to manage as Ed Miliband, the Energy Secretary, rolls out swathes of new wind and solar farms to hit net zero.
Grid instability occurs when energy demand is low, but renewables still generated large amounts of power. If not counterbalanced, this can trigger blackouts.
But many onshore solar and wind farms are not directly connected to the main transmission system and cannot be managed by Neso, which is tasked with keeping electricity networks stable.
1404 Wind and solar demand could be higher than generation
It means they must balance the system in other ways, such as paying larger power plants to turn off or paying consumers to ramp up demand.
The amount of solar on the grid has more than doubled to 22 gigawatts in the past decade, as households and businesses have sought to cut their power bills by installing rooftop panels.
But this is also leading to less demand for energy on the National Grid.
In its report, Neso said there was a 75pc chance that national demand would plunge to a new record low during the late May bank holiday weekend, as households are less likely to be at home.
The previous record of 12.8 gigawatts was set last May – but this year, grid chiefs expect it could drop as low as 11 gigawatts.
By comparison, passive generation from wind and solar farms could be around 18 to 19 gigawatts at the same time.
The imbalance highlights the challenges posed by a renewables-based electricity grid, where supply becomes heavily dependent on the weather.
One expert also warned it had echoes of the blackouts across the Iberian Peninsula last year, when a chain reaction involving solar farms knocked out power across Spain.
Under Labour’s clean power plans, Mr Miliband is seeking to triple solar capacity across Britain by 2030.
Mr Miliband loosened planning rules so more solar farms are built and approved the country’s biggest project so far in Lincolnshire last week.
Kayte O’Neill, Neso’s operating chief, said: “The complexity of operating the system at low demand is increasing, and we may need to use more of our tools and use them more often than in previous summers.
“Our analysis shows that low demand is increasingly driven by weather patterns – most notably solar photovoltaic generation – rather than underlying consumer behaviour.”
She said grid bosses were “confident we have the right tools to enable the safe, reliable and efficient operation of the system”, including a newly expanded demand flexibility service that will pay people to use surplus power.
Ms O’Neill added: “This will enable households and businesses to support system flexibility by shifting demand, increasing the range of everyday actions available to our control room at times of low demand.”
‘It is free power’
Adam Bell, a Stonehaven consultant and a former Whitehall energy department official, said Neso faced a challenge of “making sure the grid remains stable”.
He said: “They don’t have the ability to turn this solar generation off, so instead they want to turn consumption up and that could actually be good for households and heavy industry – it is free power.”
However, Kathryn Porter, an independent energy consultant, warned that the solar power glut raised fresh questions about the scale and pace of Labour’s net zero rollout.
She said: “Once again, we’re seeing Neso putting behaviour change by consumers front and centre, and saying that having consumers change their behaviour to help balance the system – instead of expecting the system to serve them.
“But also, why the hell do we keep building more solar if we’re already at a position where we’re generating more electricity than we need? That is only going to make this problem worse.”
A government spokesman said: “The independent system operators have confirmed a positive outlook for the UK’s energy supply, with both electricity and gas expected to comfortably meet demand this summer thanks to our diverse and resilient energy system.
“As the current conflict in the Middle East shows, the best way to increase Britain’s energy security long-term is by accelerating to clean homegrown power that we control, including renewables and nuclear.”