Britain's wind farm owners face a tax raid from John Healey to stop them profiting from surging gas costs.
Over the next decade, more than 3,000 renewable projects face a windfall tax of at least 55pc on the profits from power sales.
The plans, announced by the Chancellor, are designed to force them onto fixed prices for the power they generate and stop them profiting from lucrative subsidies.
Thousands of wind farms signed up to an old subsidy scheme, known as the Renewables Obligation Certificate (ROC), which lets them sell their power at prices set by gas-fired power stations.
This scheme was halted to new entrants in 2017, but those registered before then can claim subsidies up until 2037, with the legacy scheme set to cost bill-payers £8bn.
The Department for Energy Security and Net Zero has published detailed plans about the electricity generators levy, which attempts to force them off the lucrative scheme.
It is hoped the windfall tax will encourage windfarm operators to move to Contracts for Difference, which would guarantee generators a minimum "strike" price but also be a cap on what they could charge.
A similar scheme has already been agreed with EDF for the output from ...