Blackouts sweep the country in electricity shutdown

Britain was hit by electricity blackouts as a string of power station shutdowns wreaked havoc on the national generating system yesterday.

National Grid issued a highly unusual plea to electricity suppliers to reduce the voltage to homes after a raft of power plant closures threatened a supply shortage during the hours of peak demand last night.

The operator of the country's power grid sent out its plea after several regions, including south-west London, Merseyside and Cheshire, suffered power cuts following the unexpected shutdown of British Energy's Sizewell B nuclear reactor during the morning. British Energy refused to reveal the reason for the incident but said it had already begun to get the plant up and running again. National Grid cut off supplies automatically to "protect the integrity of the network," a spokesman said.

As the day wore on, however, a total of nine power stations shut down for various reasons, forcing National Grid to issue three increasingly urgent notices. The last – a so-called "demand control imminence" notice – is rare and is sent out about once every four years. It was issued yesterday after it became clear that the country's electricity supply could fall short by about 400 megawatts – equivalent to just under 1 per cent of national demand.

David Hunter, an energy analyst at McKinnon & Clarke, said theincident reflected "the crumbling nature of the insufficient infrastructure on which homes and businesses depend".

A spokesman for National Grid said some customers would have noticed a "slight dimming" of the lights last night as the power delivered to their homes was reduced slightly to spread the load elsewhere.

There was speculation among energy traders that the highly unusual shutdown of so many plants at once was caused by some companies trying to cash in on the rising wholesale price of electricity by taking supply out of the market. The wholesale price jumped by 13 per cent yesterday as the margin between supply and demand tightened.

However, others experts said this was unlikely because any generator that closed down a plant had to buy the power to cover its commitments. More power was pumped into the grid as a result of the notices and National Grid said it expected it to be "business as usual" today.