If Boris Johnson really wants us to ditch boilers for heat pumps, he needs to put his foot on the gas

After the announcement of a new £5,000 grant to go towards the installation of heat pumps in UK homes, Darren Snaith argues that while the scheme sounds good, it needs far more development if it is to contribute to pushing for net zero. 

Heating has been responsible for more than a third of our carbon emissions, making it the single biggest contributor to our carbon footprint. And with the 25 million households heating their homes by gas boilers accounting for a significant proportion of this, the Government knows that getting people to ditch their gas boiler will be crucial in helping meet the net zero target on carbon emissions by 2050.

So it was no surprise that the Government's long-awaited strategy on how to achieve net zero focused on heat pumps, with a £5,000 grant offered as an incentive from next April, over a three year period, to persuade people to wave goodbye to their boiler.

Heat pumps work like a fridge or air conditioner in reverse: warmth is extracted from the air outside by a cold refrigerant, compressed using electricity to further increase its temperature, with the hot refrigerant then heating a water source. This heat is then sent to radiators or underfloor heating, with the remainder stored in a hot water cylinder for showers, baths and taps. Heat pumps use electricity to run – but less energy than the heat they produce – making them a much more energy-efficient way to warm homes.

Most people also want to heat their homes in a way that's better for the environment: according to a recent survey carried out for RSK before the Government's announcement, the vast majority of householders – 80 per cent – are willing, in principle, to change the way their home is heated and a similar percentage would consider buying a low carbon alternative, such as a heat pump.

So far, so good, then. However, in practice, the grant may not make much difference as the high costs of heat pumps will mean a reluctance to replace gas boilers. Older homes might need bigger radiators and better insulation, both of which can add to the basic installation cost. It's estimated only 18 per cent of UK homes would be suitable for existing heat pump technology without at least some insulation being fitted. While a replacement gas boiler can cost around £1,000, an air source heat pump and full system installation can cost – depending on aspects such as the size of the home and the complexity of the installation – up to £18,000.

RSK's survey found more than one in three people would need a grant of more than 50 per cent of the cost – so the £5,000 offered will not be enough to encourage the majority to switch.

The Government needs to seriously consider increasing the grant available, and extending it beyond the proposed three year duration, if it really wants to persuade more people to install heat pumps, and if Boris Johnson is serious about making inroads in reaching net zero. The Business Secretary, Kwasi Kwarteng, has said the costs of heat pumps will fall very quickly as firms begin to invest in alternatives and consumers could benefit in as little as five years – but that's some time off, and by then, the subsidy scheme will have closed.

The Government also needs to look at infrastructure. The UK heating appliances manufacturing sector is dominated by oil and gas boiler manufacturers so it needs to provide incentives, as Mr Kwarteng has suggested, to help the industry adapt which will allow costs to fall.

The Government's strategy had already been put off for too long because of squabbling over how to foot the bill in funding the domestic transition away from fossil fuels. But surely, given the climate emergency, there's no time to lose in subsidising green retrofitting now, lowering costs for the future. If Boris Johnson really wants to deliver a home heating revolution, he needs to put his foot on the gas now.