British households have been warned on Tuesday they must prepare for blackouts, by keeping torches and warm clothes to hand.
Energy companies in the UK have suspended all non-essential staff and are bracing themselves for shortages in engineers.
The National Grid has said they can cope with the surge as people are now largely working from home and are self-isolating.
However, UK Power Networks who provides electricity to London and the southeast have written to vulnerable people advising them of what to do in the event of a blackout.
In a letter seen by the Daily Telegraph, it states customers are advised to keep a “ torch handy” and “a hat, gloves and a blanket.”
Those who have a disability, elderly, have a medical condition or are vulnerable must keep a power bank for their mobile phone, in case the battery runs out.
They advise that food can keep in the fridge for up to six hours and food in the freezer can keep up to 24 hours.
UK Power Networks said it was “postponing lower priority work” but all essential work will continue “including fixing power cuts on the rare occasions they happen.”
They added, “Put simply, our top two priorities are the safety of our staff and customers and keeping the lights on, so that essential services are provided to our communities and that today’s high-tech lifestyles can continue.”
Nicola Shaw, UK executive director for National Grid said, “In fact, demand across the country is expected to reduce; largely owing to a decrease in energy use from industrial consumers, which is likely to be greater than the increase in domestic demand as people stay at home.”