National Grid has reassured the government that Britain has enough spare energy capacity to keep the country's TV sets on in the event of England making it to the World Cup final energy secretary said yesterday.

If Roy Hodgson's team reach the final, which kicks off at 8pm UK time on Sunday 13 July, the Grid's analysts have calculated that demand for power could outstrip royal weddings and beat the previous record, when the 1999 solar eclipse caused a surge equivalent to 1.3m kettles being turned on simultaneously. However, the Grid has assured Ed Davey that it can cope with a potential record domestic energy surge.

Davey made his assurances on the World Cup while warning that Britain may have to use "last resort" measures to avoid winter blackouts in the next two years. Businesses will be paid to shut down at peak times so that there is enough energy for households.

Highly viewed events such as the World Cup cause surges in demand for electricity, especially if they are held during the evening peak when cookers and other appliances are running.

Davey told the Economist's UK energy conference: "Can you imagine what would happen if, at a crunch moment, perhaps when England are beating Brazil three nil, and our brave boys trot off for half-time, there was a mass blackout?

"The peak of all peaks, ever, arrives, and our electricity system falls over."

"I can report that National Grid have assured me that the UK has enough electricity generating capacity ready to meet any World Cup spike - through the group stages and beyond to history."

Bookmakers' odds, however, rate such a grid-straining surge as unlikely. William Hill has England at 25-1 to win the tournament – joint sixth favourite with five other teams and lagging far behind favourites Brazil at 3-1 and Argentina as the second most likely victors at 4-1.

Under the "last resort" measures National Grid is to invite businesses to bid for inclusion in a programme that pays them to reduce their power use on winter weekday evenings.

The company will seek large energy users with flexibility to reduce their usage for the next two winters. National Grid also wants to encourage energy generators to make their power stations available when they might otherwise be inactive.

Tenders may be required for two more winters but National Grid expects possible shortfalls to be eliminated by the winter of 2018/19. By then the government's plan for a capacity market should be working fully.