Stormont’s Economy Minister has expressed frustration at a lack of movement on closing Northern Ireland’s troubled renewable heat incentive (RHI) scheme.

The botched green energy scheme became controversial when it emerged in 2016 that subsidies for burning the less-harmful wood pellets offered, were higher than the fuel costs.

An Audit Office report into the scheme said “serious systemic failings” would hit the Northern Ireland budget to the tune of hundreds of millions of pounds.

The scandal contributed to the collapse of devolved government in Northern Ireland in January 2017, when former deputy first minister Martin McGuinness took issue with the DUP’s handling of the scheme.

Since then, revised tariff rates were introduced, substantially reducing payments to scheme members.

While the scheme falls under the Department for the Economy, devolved government has been through a number of years of dysfunction, from 2017-20, and again from 2022-2024.

The Northern Ireland Affairs Committee at Westminster is investigating the implications of a Court of Appeal ruling earlier this year that the decision to reduce tariffs was lawful.

Economy Minister Conor Murphy was asked for an update on closing down the non-domestic RHI scheme during questions for his department on Monday.

He said it was “frustrating” that the future of the RHI scheme is “still undecided”.

“It is a problem that I inherited and a problem that should have been dealt with long ago,” he told MLAs.

“A permanent solution, as raised at last year’s Court of Appeal judgment, is necessary for all legitimate participants in the scheme and for the taxpayer.

“Delay risks further litigation and the urgent need to close the scheme is underlined by Ofgem withdrawing their administrative services by April 2026 at the latest.

“I first circulated an Executive paper on April 4 this year. It seeks to uplift tariffs and confirm the Executive’s intention to close the scheme.

“This confirmation is needed if my officials are to develop a detailed proposal for closure and to negotiate with Treasury on using funding available for another scheme. It is frustrating that the Executive has not been allowed to make a decision on the future of RHI.”

Mr Murphy added: “Not to be able to have this discussed and debated in the Executive is extremely frustrating, and I’ve tried on a number of occasions now and I intend to bring this matter back to the next available Executive, and I hope it is sooner rather than later.”

UUP MLA Steve Aiken asked how much money it would cost to close the scheme.

Mr Murphy said his officials have not been able to calculate the cost of closing the scheme without a decision by the Executive to close it.

“That’s what I’ve been bringing to the Executive now for a number of weeks, and unable to get a decision or even get a discussion,” he said.

“We need that decision to be taken, then on the back of that we will go off and do the calculations and I will bring a further paper to the Executive to outline the costs, the possibilities of funding to support that, and allow the Executive then to take a fuller decision.”