It could happen here - generators are not producing enough spare capacity

A leading energy specialist warned yesterday that similar power cuts to those affecting the US could happen in Britain because electricity generators are reluctant to produce enough spare capacity to meet unexpected surges in demand.

Professor Ian Fells of Newcastle University, a former government adviser on energy, said that adequate spare capacity was essential but expensive and that power companies are reluctant to spend the money on making sure extra electricity is generated.

Britain used to operate on about 25 per cent spare capacity - the amount of electricity generated above the maximum expected demand - but this has now slipped to 16 per cent because power companies are operating on very tight margins because, they say, of the relatively low cost of electricity.

A more extreme version of the same problem appears to have helped to create the conditions that led to the biggest blackout in history across the east coast of America. "It could happen here. People just don't carry the spare capacity they used to. It is a market system and spare capacity costs money,'' Professor Fells said.

When Britain's electricity grid was in the hands of the Central Electricity Generating Board the spare capacity was running at 28 per cent, Professor Fells said. Now, the spare capacity of the British grid is about 16 per cent which is below what specialists such as Professor Fells believe is an adequate margin of safety.

A spokeswoman for National Grid Transco, which operates the power grid in Britain, said generating companies are being encouraged to produce more electricity to boost the spare capacity.

"We're forecasting that there will be enough electricity generation to meet demand but we would like a larger buffer zone,'' she said.

The problem is that electricity supplies have to be managed on a second-by-second basis because it cannot be stored, unlike gas. But some electricity generating companies have mothballed power plants because they are not making high enough profits to justify continued production. "Having spare capacity in the network is expensive to the point that you keep it to a minimum. But what is surprising is how vulnerable the supply industry is not just in the United States but in Europe,'' Professor Fells said.

Society is becoming more dependent on electrical devices, including computers. This means a power cut has a far greater economic impact than 20 or 30 years ago.