The minister responsible for decarbonising Scotland’s homes has admitted that “an extraordinary scale of expansion” in installing heat pumps is needed.

Patrick Harvie told MSPs that at least 100,000 electric heat pumps would need to be installed in homes a year by the end of the decade, but stressed the ambition remains on track.

The Greens minister was speaking after a new report from WWF Scotland revealed that Scotland was set to significantly miss a 2030 target for one million homes to have low-carbon heating systems by 2030.

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Modelling for the new study has found that the SNP-Greens government is set to “miss our crucial 2030 climate target”, adding that “annual emissions from homes in 2030 could be over double the government’s ambitions”.

The Scottish Government missed a target for 11 per cent of non-electrical heat to be generated by renewables in 2020 with the proportion at just 6.4%.

Speaking in Holyrood, Mr Harvie said that the Scottish Government has “continued to develop an ambitious programme of work” around the heat in buildings strategy.

He added: “In recent years, we have been reaching the level of a few thousand installations per year, but we need to reach significantly more than that—perhaps 100,000 installations or more by the end of the decade.

“An extraordinary scale of expansion is therefore required.

“We are clear that the ambition is matched by the actions that we are taking.”

Mr Harvie acknowledged that the new analysis by WWF Scotland was “both welcome and challenging”.

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He said: “On the key issue of regulation that the report identifies, we will consult very soon on proposals for a heat in buildings bill that is designed to give a very clear signal on how and when climate-friendly heating systems and improved energy efficiency measures will need to be installed.”

Labour’s Colin Smyth said: “The WWF report is clear that the Government will fall short of its target for decarbonising a million homes by 2030.

“Concerns also remain about the costs to households of making the changes that we need to see happen.

“Does the minister accept that, if we are serious about achieving a just transition, more needs to be done to ensure that the cost of such changes does not land on the shoulders of the people who can least afford them—not least given that we are still facing a cost of living crisis?”

Mr Harvie pointed to grants of up to £7,500 being made available for homeowners wishing to install a heat pump.

He added: “We also need to put pressure on the current United Kingdom Government if there is to be any hope of that happening.

“Mr Smyth might have colleagues in that Government before too long anyway, and he will need to put pressure on them to do what the UK Government has not done so far by rebalancing energy prices so that electricity and zero-emission heating systems are more affordable for people to run.”