A businessman who specialises in green energy systems has insisted heat pumps “are suitable for the vast majority” of Scottish homes as he hit back at criticism of the Scottish Government’s sustainability strategy by a peer.

Labour peer Lord Haughey had criticised Zero Carbon Buildings Minister Patrick Harvie for encouraging Scots to clean up their heating systems by replacing fossil fuel boilers with heat pumps.

Lord Haughey claimed that air source heat pumps are flawed and called on the Scottish Government to change course.

It comes after the Herald on Sunday revealed that Mr Harvie is set to penalise fossil fuel boilers in a shake-up of energy efficiency standards to encourage people to switch to green heating systems such as heat pumps.

Read more: Gas boilers set to be penalised under energy efficiency overhaul

Lord Haughey told The Herald that heat pumps are not appropriate for Scottish homes, a claim rejected by the Scottish Government and businesses.

He also called on Mr Harvie to instead pursue encouraging people to replace their fossil fuel boilers with electric boilers.

But concerns have been raised that electric boilers cost three times as much to run.

Peter Chalmers from the Greener Energy Group, a Scottish business that speciailises in energy efficiency, has hit back at Lord Haughey’s claims.

Speaking on Good Morning Scotland, Mr Chalmers said: “Lord Haughey was going on to say that heat pumps don’t work.

“His alternative was to install an electric boiler – which might be a cheaper alternative to heat pump to initially install, but the running costs would be three times more expensive than a gas boiler or a heat pump.

“And I don’t know many people that want to triple their energy bills right now.”

In response to the criticism about the suitability of heat pumps, Mr Chalmers stressed that “heat pumps are suitable for the vast majority of properties”.

Read more: Harvie urged to halt heat pumps strategy and back electric boilers

He added: “If a reputable company goes to a property and finds that a heat pump isn’t suitable, then they should either find a different solution for it or indeed walk away from it.

“We have many different options for consumers now and for us, it’s all about finding the right mix of products and giving the customer the choice in a product that’s best suited to them.

“Every customer that has a heat pump installed will say their house has never been warmer, their bills have never been lower and they’re delighted with it.”

The Scottish Government has made thousands of pounds available in grants to help people switch to a heat pump.

In December, the Scottish Government moved to make it simpler and more affordable for people to install heat pumps with a standalone grant of £7,500 from the Home Energy Scotland scheme made available as well as an extra £1,500 to homeowners in rural areas.

Read more: Half of Scots support Harvie's plan to phase out fossil fuel boilers

A survey commissioned by WWF Scotland revealed that more than half of Scots would install a heat pump with some or no government support, while 40% would do so within the next five years.

Mr Harvie said although Scotland’s net zero aim is to decarbonize by 2045, “we’re starting now and we need to accelerate”.

He added: “So this is not far-off futuristic technology, heat pumps are a very well tried and tested technology.”

Mr Harvie said companies are investing in smaller, more efficient heat pumps, adding: “That’s where the innovation is going. That’s where the industry is going.

“And I genuinely hope that Willie Haughey chooses to invest a bit in R&D and catch up.”