Swedish energy giant Vattenfall wants to build the Norfolk Boreas wind farm in the North Sea about 70kms east of Happisburgh.
But the government has pushed back its examination period for the project six months, until October 12.
The Planning Inspectorate asked for the delay because hearings have had to be cancelled, meaning residents’ groups and other parties involved would not have had their say on the project.
Graham Davey, project manager on Boreas, said: “This delay is one of the many unfortunate consequences of the Covid-19 pandemic, and not linked to the application itself.
“As final hearings were cancelled, the examining authority asked additional questions and everyone has been able to make their views known.
“We are confident that there is very little left to explore, and that it will be possible to complete the process well within the five-month limit provided by the secretary of state.”
The wind farm would mean running a 60km cable trench from Happisburgh to Necton, near Swaffham, where a substation would be built to connect it to the National Grid.
Boreas, together with another planned Vattenfall wind farm called Vanguard to be built nearby, could power more than 3.9 million UK homes.
Jenny Smedley from the Necton Substations Action Group said: “I was surprised by the length of the delay but it just goes to show how many problems there are.
“Presumably after the examination period there will be another six months of consideration by the planning inspector and secretary of state before a decision is made.”
The group has been lobbying for an Offshore Ring Main (ORM) so that Vattenfall’s and other wind farms would not need to run separate cable trenches through the countryside, but instead meet up at sea so they could all connect to the grid via a single route.
Simon Gray, chief executive of the East of England Group (EEEGR), which represents nearly 300 businesses across the energy sector, said: “We are increasingly hearing calls from people wanting to see a newer, greener future emerge as we plan a roadmap to lead us out of the Covid-19 pandemic.”