and why anybody who thinks renewables can possibly fill the gap needs a reality injection. Extra large. Blackouts affect thousands in Britain's worst power shortage in four years "National Grid issued "a demand control imminent" warning â something it is forced to do no more than once every four years â as nine power stations fell out of action. The most notable was Sizewell B, the nuclear power station near Leiston, Suffolk. The plant was closed for "unexpected maintenance", which the company said was no cause for alarm." "It shut down within two minutes of Longannet, a coal-fired power station in Fife, Scotland, also unexpectedly shutting down. The two power plants supply six per cent of the nation's electricity. The unusual coincidence of both plants closing down caused power cuts across parts of London, Kent, Merseyside and Cheshire. It is understood that tens of thousands of homes were affected, possibly more. Power was resumed within two hours. However, National Grid had a further crisis on its hands when a total of nine power stations fell out of action during the afternoon, leading to a shortfall of 400 megawatts of power â one per cent of the country's total daily needs."