Heatwave: United Kingdom’s capital London narrowly avoided a power blackout last week

Britain paid the highest price on record for electricity in London last week as the capital narrowly avoided a power blackout, it has emerged.

National Grid paid £9,724 per megawatt hour, more than 5,000% than the typical price, to Belgium on Wednesday to prevent south-east London losing power.

The hottest UK days on record led to power system constraints amid high demand.

London Fire Brigade reported its busiest day since World War Two.

Hundreds of fires across the city put strain on the city’s emergency services with just three fire engines left at one stage.

Increased demand for energy across Europe, combined with a bottleneck in the grid, forced National Grid’s Electricity System Operator (ESO) to buy electricity from Belgium at the highest price Britain has ever paid to keep power flowing.

Other factors, including planned maintenance outages of overhead lines and a storm in Belgium impacting solar power, put the system under severe strain.

While the amount bought at the record amount was minimal, reportedly enough to supply eight houses for a year, it has exposed the UK’s reliance on importing electricity from interconnectors overseas, particularly France, Belgium and the Netherlands.

A spokesperson at National Grid ESO said that while other generation was available on Wednesday, power outages during the summer period meant a specific circuit was needed to get electricity to the right place.

They said: “We were bidding in a tight market and market prices were high that day because Europe also wanted the energy.”