National Grid makes figures public for first time as government considers cutting windfarm subsidies before election
National Grid made special payments of £300m over the last 12 months to big energy companies sometimes for switching off their power stations in an attempt to "balance" the system.
The huge payout dwarfs the £37m paid to windfarms to remain offline over the same period to the end of February a figure used by critics to question the advisability of supporting renewable energy.