Liz Truss has said the UK “can get through the winter” amid warnings that planned energy blackouts could be needed for the first time in decades.
The Prime Minister said the UK has “good energy supplies” although stopped short of explicitly offering a guarantee of no blackouts, in response to concerns from the body that oversees Britain’s electricity grid.
Households are being encouraged to help avoid blackouts, “save money and back Britain”, by using more energy during off-peak times.
In what it called an “unlikely” scenario, the National Grid Electricity System Operator (ESO) said that households and businesses might face planned three-hour outages to ensure that the grid does not collapse.
Planned blackouts hit the UK during the 1970s in response to the miners’ strikes and the oil crisis.
There have also been major unplanned outages during storms, including in 1987 when more than 1.5 million people were left in the dark.
But the lights will stay on this winter unless the gas-fired power plants that produced 43% of Britain’s electricity over the last year cannot get enough gas to continue operating.
It is the most dire of three possible scenarios that the ESO laid out on Thursday for how Britain’s electricity grid might cope with the worst global energy crisis for decades.
In the other two scenarios, the operator hopes that by paying people to charge their electric cars at off-peak times, and firing up back-up coal plants, it can offset the risk of blackouts.
Ms Truss told reporters during a visit to the Czech Republic: “We’re working very hard on energy security, it’s one of the reasons I am here in Prague today.
“We have interconnectors with our European partners, we’re working on more gas supplies, we’re working on building out nuclear energy, building out wind energy, so we do have a secure supply of energy.”
Pressed to guarantee there will be no blackouts, Ms Truss replied: “What we’re clear about is that we do have a good supply of energy in the UK, we’re in a much better position than many other countries, but of course there’s always more we can do, and that’s why I’m here working with our partners, making sure we do have a secure energy supply into the future.”
Ms Truss added: “We do have good energy supplies in the UK, we can get through the winter, but of course I am always looking for ways that we can improve the price for consumers.
“That’s why we put in place the energy price guarantee as well as making sure we have as much supply as possible.”
Ms Truss has previously said she would not be telling people to ration their energy use this winter, as Russian president Vladimir Putin limits gas supplies to Europe in retaliation for sanctions linked to the Ukraine war.
During the Conservative Party leadership contest, Ms Truss also said there would be no energy rationing.
She has since offered a multibillion-pound price guarantee which will prevent average annual household bills going past £2,500.
For Labour, shadow climate secretary Ed Miliband said: “Today’s report from National Grid shows our vulnerability as a country as a direct consequence of a decade of failed Conservative energy policy.
“Banning onshore wind, slashing investment in energy efficiency, stalling nuclear and closing gas storage have led to higher bills and reliance on gas imports, leaving us more exposed to the impact of Putin’s use of energy as a geopolitical weapon.
“Yet still the Conservatives fail to learn the lessons.”
Liberal Democrat leader Sir Ed Davey called on the Government to convene the emergency Cobra committee to address the possibility of blackouts.
He said: “A failure to act now could see millions plunged into rolling blackouts whilst petrol and heating oil prices spiral even further out of control.”
The margins between peak demand and power supply are expected to be sufficient, and similar to recent years in the National Grid ESO’s base case scenario for this winter.
But in the face of the “challenging” winter facing European energy supplies following Russia’s invasion of Ukraine, the grid operator is also planning for what would happen if there were no imports of electricity from Europe.
To tackle a loss of imports from France, Belgium and the Netherlands, there are two gigawatts of coal-fired power plants on standby to fire up if needed to meet demand.
National Grid Gas Transmission separately said that while gas demand will increase this winter, it expects Britain to be able to get enough gas to take it through a “Beast from the East” scenario or a long, cold winter.
People are being encouraged to sign up with their electricity supplier to a scheme which will give them money back on their bills to shift their use of power away from times of high demand, to help prevent blackouts.
Households tend to consume a fifth of their daily energy between 4pm and 7pm, according to data from Ovo Energy. The supplier on Thursday said its customers could save £100 if they signed up to use energy at off-peak times.
In addition, larger businesses will be paid for reducing demand, for example by shifting their times of energy use or switching to batteries or generators in peak times.
Without the scheme, there might be days when it was cold and still, creating high demand and low levels of wind power, when there would be a potential need to interrupt supply to some customers for limited periods, National Grid ESO’s winter outlook said.
The ESO also said that if there is not enough gas to keep the country’s power stations going in January it could force distributors to cut off electricity to households and businesses for three-hour blocks during the day.
“In the unlikely event we were in this situation, it would mean that some customers could be without power for pre-defined periods during a day – generally this is assumed to be for three-hour blocks,” the ESO said.