The prospect of overseas giants generating bumper returns in the North Sea oil and gas business with taxpayer support has outraged campaigners amid claims that developers of the Rosebank field off Shetland could get tax breaks worth billions.

However, Canadian investors have underlined how much money corporations based outside the UK expect to make in the renewables business without attracting much comment.

News this month that Norway’s Equinor and Israeli-owned Ithaca Energy have won official approval for plans to develop Rosebank provoked howls of despair from the likes of Friends of the Earth Scotland.

Claiming the 300 million barrels that may be produced from the field will fuel a climate catastrophe, they dismissed suggestions the development could generate big benefits for the UK in terms of energy security and supply chain investment.

As Equinor expects to sell crude from Rosebank on the open market, critics insist there can be no guarantee that any of it will remain in the UK.

READ MORE: BP highlights opportunities off Shetland after posting $2.6bn profit

Friends of the Earth Scotland campaigner Lauren MacDonald said Rishi Sunak had committed a destructive and pointless act of vandalism by approving Rosebank, which she insisted would do nothing to lower fuel bills.

She lamented: “Rosebank’s oil mostly belongs to Norway, and the majority will be shipped abroad and then sold back to us at market price.”

Assurances from Equinor that the UK will get oil from Rosebank if it needs it, while gas will go into the country’s pipeline system, cut little ice.

Friends of the Earth Scotland’s indignation was fuelled by its calculation that Rosebank could benefit from tax breaks worth £2.8bn under the generous investment allowance that was introduced by the UK Government alongside the windfall tax in 2022.

Under this, firms can set the money spent on developments against the windfall tax payments they are due to make.

“Handing over billions in tax breaks for oil for export makes zero sense to the millions of ordinary people in this country who can’t afford their heating bills,” claimed Ms MacDonald.

Equinor said it did not recognise the numbers cited by Friends of the Earth Scotland. The company, which is majority-owned by the Norwegian government, highlighted estimates by Wood Mackenzie and Voar Energy that Rosebank will contribute £26.8bn to the UK through tax payments and investments into the economy.

READ MORE: Tax refund for oil firm that cut 350 North Sea jobs

Friends of the Earth Scotland could still be right to suggest the investment allowance may have been a big factor in Equinor deciding to proceed with Rosebank, after it complained about the windfall tax.

However, some people might find the reference to Equinor’s Norwegian ownership surprising coming from an organisation that would probably have no truck with nationalistic sentiments in the context of the global climate crisis.

Friends of the Earth Scotland may not want to see the UK Government trying to maximise earnings from fields such as Rosebank by leaving them under the control of a state-owned firm in the way that Norway has.

Equinor’s partner in Rosebank, Ithaca Energy, is owned by Israel’s Delek Group.

It was notable that Friends of the Earth Scotland highlighted overseas involvement in Rosebank as a $1 billion (£0.8bn) renewables deal provided a reminder that foreign firms have positioned themselves to profit handsomely from the drive to reduce the UK’s reliance on oil and gas.

The deal in question will see Canadian investment giant Brookfield buying the onshore windfarm portfolio developed by the family-owned Banks group.

READ MORE: Scottish Government dithers as investors cash in on renewables boom

The portfolio includes operational windfarms in Scotland and a pipeline of assets that are under development, such as a battery storage park in Bathgate. Banks has headquarters in County Durham and a base in Hamilton.

Brookfield clinched the deal despite fears the wind power development drive in the UK could stall amid claims the Government is not providing enough support to help firms deal with big cost increases.

Developers of offshore windfarms snubbed the latest official support round complaining the Government would not guarantee prices for their output that would be high enough to assure them of a decent return on investment.

The Contracts for Difference (CfD) round was notable for the fact that developers of onshore windfarms applied successfully for support after being excluded from the scheme temporarily following concerns that too many developments were springing up across the UK.

READ MORE: Renewables projects in Shetland and Orkney win official support

The costs of the CfD programme are added to household energy bills, which have surged amid the fallout from Russia’s war on Ukraine.

Renewables champions, however, have appeared to focus attention on the windfall tax imposed on power generators from January. They were outraged that windfarm developers were not offered an investment allowance along the lines of the one made available to oil and gas firms.

Calls for something to be done increased in volume last month when Cheshire-based Community Windpower halted work on a big development in southern Scotland.

Community Windpower said the expected cost of the Sanquhar II development had increased from £300m to £550m in recent years and complained about the “unfair” windfall tax.

However, Brookfield’s swoop on the portfolio amassed by Banks shows investors based outside Scotland think they can still make plenty of money in the renewables business in the country.

READ MORE: Poverty crisis in Scotland set to deepen warns former prime minister

The executive who led the deal for Brookfield, Sebastian Perl, told the FT the firm thought there was “generally a very positive outlook” for renewables in the UK.

“There might be some challenges along the road but you have that with every market, every business. It hasn’t changed our view on the market or the investment environment in the UK,” noted Mr Perl.

He said the windfall tax was not a “showstopper”.

Windfarm developers tend to sell the power they generate on long term contracts that offer protection against inflation, which firms in other sectors would envy.

Brookfield showed its belief in the appeal of energy assets in Scotland before the Banks deal.

In 2021 it teamed up with the Ontario Teachers Pension Plan Board to buy a stake in the SGN gas networks business from Scottish energy giant SSE, for £1.2bn.

Brookfield has submitted plans to build a windfarm at Armadale on the Sutherland coast, which is expected to be producing power for 30 years. This underlines the fact that windfarms can now have much longer operating lives than were expected a few years ago. The profits firms can make on their investments in such assets may be much bigger than originally forecast.

On its website, Banks says it has applied to extend the lives of Middle Muir and Kype Muir windfarms in South Lanarkshire for up to 15 years, noting: “The current technology is now expected to continue to operate at a safe and efficient level for longer than original estimates predicted.”

The Muir windfarms were completed in 2018 and 2019 respectively with expected operational lives of 25 years.

If the extension applications are successful Brookfield could be making money in Lanarkshire for decades.