Could a heat pump be the answer to heating your home in winter?

This article has been updated. It was first published on 1 February, 2023.

Heat pumps could make our homes, workplaces and public buildings more sustainable while increasing energy security. Thanks to soaring energy prices, they are also on course to become the cheapest heating option.

Globally, heat pumps could reduce CO2 emissions by 500 million tonnes by 2030 as they replace gas, oil and coal, says the International Energy Agency (IEA). In Europe alone they could cut the need for gas imports by 21 billion cubic metres. And according to the World Economic Forum's report, Fostering Effective Energy Transition 2023, heat pumps should form part of a raft of solutions in the energy transition.

Heat pumps are already cheaper to run than conventional boilers, but their high initial cost is deterring some people from buying one, the IEA says. Countries will need to subsidize installations if they are to achieve their climate targets, the IEA warns.

“Government support is essential to help consumers overcome upfront costs and tap into the savings heat pumps provide,” says the IEA’s Executive Director, Dr Fatih Birol. “This is an urgent priority to shield low‐income households from the energy crisis."

Some people are also concerned they lack the efficiency of conventional boilers when the temperature outside is particularly low. However, research suggests that even at temperatures well below freezing heat pump efficiency is still significantly higher than fossil fuel systems. Standard heat pumps are well suited to temperatures down to at least -10°C the study suggests, and most European winters rarely get colder than that.

So what is the potential of heat pumps? Here are five charts that show how they work and what they can do to warm our indoor spaces, while helping to stop the climate warming even further.

Heat pumps use similar technology to that of a refrigerator or air conditioner. They extract heat from a source – the surrounding air – and amplify this heat.

Heat pumps are much more efficient than boilers, because they transfer heat rather than generating it. Almost all of this heat reaches the space intended to be warmed.

The pumps can work at any temperature above absolute zero (-273°C) and the water they produce can be recycled to flush toilets or used to grow plants hydroponically. They can also work with hybrid systems using, for example, gas to top up the heat output.

The chart above shows sales of heat pumps in 2021, which were 13% higher globally than in 2020. Despite these rising sales, heat pumps only supplied 10% of heating for all types of buildings worldwide in 2021.

Total installed capacity was over 1,000 gigawatts, nearly half of which was in North America. Some of the world’s coldest nations had the highest levels of heat pump usage. Heat pumps provided 60% of heating in Norway and over 40% in Finland and Sweden, IEA says.

The extent to which heat pumps can be rolled out depends on whether nations deliver what they’ve written into their existing policies or climate pledges. In the chart above, STEPS refers to countries’ stated policies on heat pumps and APS means their announced pledges.

The IEA says government support for heat pumps – like in the US Inflation Reduction Act – is needed for nations to achieve their climate and energy security goals. Bans on new fossil fuel boilers – as in Denmark, France, the Netherlands and Norway – will also help.

Insulating buildings is a key component of improving energy efficiency and reducing emissions. The data from Denmark in the chart above demonstrates that heat pumps in the best-insulated homes use 30% less electricity than those with poor insulation.

Improving a home’s energy rating by just two grades (from D to B) can halve energy demand, the IEA says. Making buildings more energy efficient also means households can use lower-capacity heat pumps, which are cheaper to install.

For Europe, heat pumps could reduce natural gas use by 7 billion cubic metres by 2025, and 21 billion cubic metres by 2030. Energy-efficiency measures, including refitting existing buildings and mandating heat pumps in new builds, will also help cut gas usage.