The government must provide greater clarity over its offshore wind budgets if Britain is to hit an ambitious target to quadruple output from the green energy source by the end of the decade, one of the world’s largest builders of wind turbines has warned.

The UK boss of Siemens Energy, which has produced more than half of the offshore wind turbines operating off Britain’s coasts, has called on the government to set out how much support it will provide for new wind projects over multiple years, rather than on an annual basis.

Under the existing subsidies regime, developers bid for annual contracts to build additional wind capacity in exchange for a guaranteed maximum price for the power they will produce. The budget for this year’s auction was set at a record £800 million for offshore wind projects.

“If we are to quadruple offshore wind, we need that level of predictability because we also need to see what enhancements we have to do at home to support that sort of growth,” Darren Davidson, the head of Siemens Energy UK and Ireland, said.

Labour has set a target of quadrupling offshore wind, doubling onshore projects and trebling the amount of solar power by 2030.

Siemens Energy’s factory in Hull is the only maker of offshore wind turbine blades in Britain, with a workforce of about 1,300. The UK is second only to China in terms of installed offshore wind capacity, but most of the critical components for wind turbines are made overseas.

In 2022 GE Vernova, a rival that is supplying the world’s largest wind farm at Dogger Bank in the North Sea, scrapped plans to build a blade factory in northeast England after failing to secure any new orders from projects bidding in that year’s capacity auction.

Greater clarity over the level of support the government was willing to provide for new projects over a five or ten-year period would help manufacturers to overcome supply chain challenges and could encourage more factories to be built in the UK, Davidson, 51, said.

“If we’re doubling or tripling and quadrupling the number of megawatts that we’re installing in the North Sea, we need to sustainably do it over a long-term period, so we’ve got the right level of confident resources and a strong supply chain to deliver that over a longer term, rather than building up a supply chain that does it over a two or three-year period, which isn’t sustainable.”

The Department for Energy and Net Zero said: “The government will deliver the bold action needed to make Britain a clean energy superpower. We have already ended the onshore wind ban, supported new solar and our plans for 2030 will involve backing all forms of clean power.

“Our current funding round for contracts-for-difference is over £1 billion, including £800 million for offshore wind projects. Applications are being assessed and the secretary of state will carefully consider whether to increase the budget.”