Emergency measures are needed to ensure Britain avoids blackouts this winter, the National Grid boss has admitted.
Chief executive Steven Holliday said old power stations could be brought out of mothballs to supply extra energy.
A number of coal-fired power stations have been shut to satisfy EU targets for cutting greenhouse gases.
Four nuclear plants have closed unexpectedly for repairs – although Mr Holliday said two may be ready by the end of the year.
The result is the total amount of electricity that can be supplied could be just 5 per cent greater than demand from consumers.
National Grid has commissioned firms to bring mothballed power plants back into operation, and will pay manufacturers to turn off machines on peak afternoons.
Some £75million has been set aside for this over the next two winters, money that will be added to customers’ bills.
Mr Holliday said: ‘Margins are tighter than they were last winter, which were tighter than they were the year before. The reality is that a lot of our power stations are old.
‘We are taking a lot of coal fired stations off and we need to build a lot of new generation capacity in the UK.’ […]
Mr Holliday, who was speaking on the BBC Radio 4 Today programme, said National Grid is a ‘long long way’ from the need to have a conversation about whose lights would have to be turned off.
‘We are just making sure that we have back up supplies in a prudent way, so that we can see ourselves through a cold winter.’
Mr Holliday said the measures will prevent the lights going out, adding: ‘There are lots of tools available to us. We are being very prudent, very careful, but I’m confident that with these tools we will be able to balance supply and demand this winter.’
He said the Government passed a new Energy Act last year which has created a series of incentives to encourage energy companies to build the power stations, including nuclear and wind farms, that will supply needed electricity in the future.
But it raises the spectre of 1970s-style blackouts. The British Chambers of Commerce said managers had ‘failed to plan adequately’.
Big business argue the energy crunch is a damning indictment of the way the nation’s electricity supply system has been managed by successive governments and regulators.
Director of the Energy Intensive Users Group, Jeremy Nicholson, said: ‘This can’ t be sustainable way of managing the energy system. Industry has to have access to secure power supplies.
‘How are we supposed to expect investment to continue into this country if we are in danger of moving toward having Third World levels of reliability for power?
The British Chambers of Commerce said radical action is needed to ensure homes and businesses have all the power they need.