But he added that the size and scale of new developments would depend on local consent through the planning process.
“Would local people be happier to have larger, taller turbines, but fewer of them – about half the number – that’s yet to be tested out,” he said. “It would then be up to a local community to decide which of those options and probably some things in between that they thought was acceptable.”
There are no specific restrictions in current planning rules on the height of turbines.
In Scotland, which hosts the vast majority of the UK’s onshore wind because its planning rules are more relaxed, the average height of turbines is 102.4m from the tip of the blade to the ground, compared with 92.6m in England.
Nicola Sturgeon recently celebrated the construction of the country’s largest turbine, which at 200m is twice the height of the tower housing Big Ben. The current tallest wind turbine in England is 126.5m at a site in Essex.
Bank Renewables, which developed the wind farm in South Lanarkshire, said it would be looking for sites in England if the ban were lifted. But the company said the height of turbines would depend on “what the particular landscape in which it would sit could accommodate”.
Dale Vince, the founder of energy company Ecotricity, said tech developments meant that England could have “fewer, bigger windmills”, compared to the early years of onshore wind development. But he said England was not well suited to the biggest turbines, which he argued are not needed to provide sufficient energy from onshore wind.
Ecotricity has a “back catalogue” of planning proposals from before the ban was imposed which Mr Vince said it would revisit if the rules were changed.
Among these is a proposal for a site in Gloucestershire with enough turbines to power the entire country. The proposal says this could be achieved with just 66 turbines if they are allowed to reach a height of 175m, or 118 turbines if they were limited to 125m.
‘Industrialisation of the countryside’
“You don’t always need to go so high, it depends on your terrain,” he said. “But also the context of the landscape is important and in England, I don’t think I would propose really big windmills.”
Mr Sunak supported keeping the ban during his leadership campaign in the summer and has sought to argue that the UK should instead focus on its offshore wind industry.
The Climate Change Committee, which advises the Government on meeting its net zero goals, suggests the UK needs to double its onshore wind capacity by 2030. While much of this can be developed in Scotland, it would require costly and disruptive transmission infrastructure for the electricity to reach the communities where it is needed.
A survey earlier this year by YouGov found that more than 70 per cent of respondents support wind farms in their local area, compared to 17 per cent who are opposed.
But some Tory MPs remain nervous about the possible political backlash of supporting onshore wind in their rural constituencies.
Under the 2015 rules onshore wind farms can only be built in areas that have been designated by local authorities, a task only 11 per cent of councils have undertaken.
Planning authorities must also have “fully addressed” any impacts identified by the local community, which experts say effectively gives veto power to anyone who objects.
If brought in line with other renewable projects, larger onshore wind farms over 50MW will be designated as NSIPs and approved by the business secretary rather than through a local planning process.
Mr Hayes said relaxing the ban would lead to the “industrialisation of the countryside”.
