Suitability of ‘reversible’ heat pumps to cool homes questioned

The suitability of “reversible” heat pumps, which also provide cooling, has been questioned by a heavyweight committee of MPs.

A report from the House of Commons Environmental Audit Committee (EAC) warns that the UK’s warming climate will inevitably increase demand for cooling technologies, which in turn will increase the stress of the grid.

Heat pumps have been touted as a way to cool homes as well as heat them. However, the committee has urged the government to carry out an assessment of heat pumps suitability as a cooling method.

It warns that installing reversible heat pumps, which provide active cooling, may be “unnecessary” in some cases and thereby significantly increase energy use and emissions.

Already, the report points out, coal-fired power stations have had to be brought temporarily back into service to cope with peaks in energy demand from air conditioning. UK temperatures soared above 40°C for the first time in 2022.

As well as continuing action to decarbonise the grid, the MPs say it is essential that ministers should prioritise passive cooling measures, such as open spaces, which require no energy to run and can mitigate the development of heat islands in urban neighbourhoods.

The report also urges the government to consider opportunities to combine existing initiatives on insulation and energy efficiency into a much more ambitious and comprehensive housing retrofit programme, which also addresses the risks of overheating.

This comprehensive national retrofit programme should help to adapt the UK’s housing stock for both net zero and thermal comfort, it says.

The EAC report also recommends that the Future System Operator should make specific provision for likely future demand for electricity for cooling purposes in its future scenario planning.

And it proposes that the Met Office should trial the naming of heatwaves, like it has done recently with storms, to help the public recognise how these extreme weather events can be a threat to health and wellbeing. This trial should be carried out with a view to becoming permanent if the trial is deemed successful.

EAC chair, Philip Dunne MP, said: “The world is heating up, and in the coming year we may exceed an increase of over 1.5°C above pre-industrial levels: breaking a key ambition of the Paris Agreement.

“The record temperatures we are seeing in UK summers, triggered by climate change, pose significant risks to health and wellbeing, and swift action must now be taken to adapt to the UK’s changing climate.”

He added: “Projections suggest that without action, there could be 10,000 UK heat-related deaths annually.

“High temperatures are costing the UK economy £60 billion a year: so measures to address the risks from overheating are simply a no-brainer.

“There are a number of relatively simple ways to mitigate overheating risk, such as installing shutters, increasing the size of green spaces and using reflective paint on roofs. Yet none of these measures are being rolled out at scale. There is now a real opportunity to focus on these measures in tandem with improving the energy efficiency of the country’s homes in a new national retrofit programme.

“Tackling overheating at scale will not be a quick or easy undertaking. Clear collaboration between government departments and local authorities is necessary, supported by a clear messaging campaign and a pipeline of funding and skilled retrofitters to undertake the work needed. Existing government policy fails to grasp the urgency of the task at hand. A minister with oversight on heat resilience must be appointed to oversee this important work.”

However Bob Ward, policy and communications director at the London School of Economics’ Grantham Research Institute on Climate Change and the Environment, said the report could have gone further in its criticisms of how the government is preparing the UK for future heatwaves.

He said: “This careful and measured report correctly identifies the many shortcomings in the government’s feeble approach to managing heatwaves, which are growing in frequency and intensity in the UK, killing thousands of people, and costing our economy billions of pounds every year.

“However, the report could have been even clearer that it is the abysmal state of Britain’s housing stock, with many homes too poorly designed and constructed to keep heat in during the winter and to keep heat out during the summer, that is killing thousands of people every year.”

“It is a national scandal that the government has failed to implement a nationwide retrofitting programme to make homes and offices across the country more resilient to extremes of temperature.”