A vast windfarm off the Norfolk coast has been approved by ministers for a second time after a local man convinced a high court judge to overturn the first decision a year ago. The high court verdict last February forced the government to reconsider the plans by the Swedish renewables firm Vattenfall to build two offshore windfarms capable of generating enough green electricity to power the equivalent of 4m UK homes. But on Friday Kwasi Kwarteng, the business secretary, reapproved the Norfolk Vanguard offshore windfarm, more than a year and a half after first giving the project the nod. His department approved the Norfolk Boreas windfarm, its sister project, at the end of last year. The projects were temporarily derailed last year after a legal challenge by a local resident, Raymond Pearce, raised concerns about the impact on the landscape and the view. Pearce, who lives near Reepham in Norfolk, argued that ministers had not taken into account the “cumulative impacts” of the two projects and had given “inadequate” reasons for not doing so. The concerns centred on Vattenfall’s plans for a substation for both projects about 40 miles from the coast at Necton, which would require cables to pass within 80 metres of Pearce’s house. The high court judge added that the plans had attracted “substantial objections” from the local community, too. Conservationists also raised concerns about the safety of endangered birds in the area. Work on the windfarms, located almost 30 miles off the coast, is now expected to begin in 2023 and would “help to cement and maintain East Anglia as a UK renewable energy powerhouse” that could support thousands of jobs in the local area, according to Vattenfall. Danielle Lane, Vattenfall’s UK boss, said the approval was a “major step forward for a project that will help to unlock the huge potential of offshore wind for the UK”. “We’ll be working even more closely now with local communities as we begin to take the project towards construction,” Lane said. “This will include preparatory works on the ground, but also work with our local partners to make sure we get our plans absolutely right to maximise benefits to the region.” The industry group RenewableUK said the approval would also secure “significant investment in much-needed new energy infrastructure” to help the UK meet its climate targets. “The government has set the industry a target of nearly quadrupling our current offshore wind capacity to 40 gigawatts by the end of this decade,” said RenewableUK’s chief executive, Dan McGrail. “Giving the go-ahead to a major project like Norfolk Vanguard is a big boost to help us to get there. It also demonstrates to the rest of the world that the UK is committed to taking significant practical action against climate change,” he said.