Heat Pumps
What are heat pumps?
A heat pump uses technology similar to that found in a refrigerator or an air conditioner, but in reverse, extracting heat from a source, then transferring the heat to where it is needed. Current models are 3‐5 times more energy efficient than gas boilers, and global heat pumps sales have been growing steadily over the past decade, even though they slowed down in 2023 amid higher interest rates and inflation.
What is the role of heat pumps in clean energy transitions?
Heat pumps are increasingly recognised as a critical technology for the decarbonisation of heat, receiving increasing policy support in several countries over the last years. The IEA estimates heat pumps globally have the potential to reduce global carbon dioxide (CO2) emissions by at least 500 million tonnes in 2030 – equal to the annual CO2 emissions of all cars in Europe today.
Where do we need to go?
Heat pumps still meet only around 10% of the global heating need in buildings, below the deployment level required to get on track with the Net Zero Emissions by 2050 Scenario. Further policy support and technical innovation are needed, in particular to reduce upfront purchase and installation costs, remove market barriers to complex renovations, improve energy performance and durability, and exploit the potential of heat pumps as an enabler of power system integration and flexibility.
Heat pumps
Heat pumps are increasingly recognised as a critical technology for heat decarbonisation, receiving focused policy support in several countries over the past years. In 2023 global sales of heat pumps decreased by 3%, after two consecutive years of double digit-growth, amid high interest rates and inflation in most major heating markets.
However, still meet only around 10% of the global heating need in buildings. To get on track with the Net Zero Emissions by 2050 (NZE) Scenario, the global heat pump stock would need to almost triple by 2030, to cover at least 20% of global heating needs. Further policy support and technical innovation are also required, particularly to reduce upfront costs, and to remove market barriers to renovations, improve energy performance and durability, exploit the flexibility potential, and further develop products and systems for refrigerants with lower climate and environmental impact.
Heat pumps sales stalled, only major market where heat pumps grew is China
Heat pumps sales stalled, only major market where heat pumps grew is China
Countries and regions making notable progress to advance heat pumps include:
- In the European Union, heat pumps sales fell by 5%, after a decade of steady growth. Though sales continued to grow in a range of countries, this was not sufficient to balance out a major downturn in Italy, and significant declines in Poland and Finland.
- In the United States, air-to-air heat pump sales decreased by 15% in 2023. However, sales of fossil fuel heating systems plummeted even further, by a record 20%.
- Air-to-water units declined by 10% in Japan in 2023 amid low consumer spending, mainly driven by a drop in sales of heat pumps water heaters, which had been increasing year on year since 2014.
- In the United States, nine states accounting for nearly a quarter of residential energy use have recently pledged to aim for heat pumps to account for around two-thirds of residential-scale space heating, water heating and cooling equipment sales by 2030, and 90% by 2040.
The majority of current space and water heating demand could be met with lower CO2 emissions by using heat pumps instead of condensing gas boilers
The majority of current space and water heating demand could be met with lower CO2 emissions by using heat pumps instead of condensing gas boilers
Relative CO2 emissions from the operation of air-source heat pumps compared with the most efficient condensing gas boilers by region in the Net Zero Scenario, 2010-2030
OpenIn 2023, heat pumps could meet more than 60% of global space and water heating demand with lower CO2 emissions than if condensing gas boilers are used. Rapid reductions in emissions from electricity supply and increased technology efficiency in the NZE Scenario mean that in all regions, heat pumps would record lower CO2 emissions than natural gas-fired condensing boilers before 2025.
Specialised maintenance, recycling and the use of alternative refrigerants can substantially reduce emissions resulting from refrigerant leakage
Associated with heat pumps deployment, there is a risk of accidental emissions of refrigerants, for example during manufacturing, product usage or decommissioning. Currently, most heat pumps employ a hydrofluorocarbon (HFC) as refrigerant. HFCs have a short atmospheric lifetime, but high global warming potential (GWP). HFC made up about 2.5% of 2019 global GHG emissions.
If no changes were made in refrigerant usage, the global heat pump stock in 2030 in the NZE Scenario would contain nearly 740 Mt of CO₂ equivalent from HFCs. This is more than current direct emissions in all Chinese buildings; but, due to short atmospheric lifetime has an even higher short-term climate impact.
Good practice in maintenance and recycling applied worldwide could prevent the emission of about one-third of these HFCs but the estimate varies widely by geographical region and heat pump model. New generation HFC refrigerants feature a lower GWP than conventional HFCs, but are still significantly more potent GHGs than hydrocarbons or HFOs, which are considered possible alternatives to HFCs. However, hydrocarbons require additional safety precautions for flammability and HFOs require further research in the field of toxicity and atmospheric decomposition.
Under the NZE Scenario, heat outputs from heat pumps increase at least two-fold by 2030
Under the NZE Scenario, heat outputs from heat pumps increase at least two-fold by 2030
In 2023 heat pumps met more than 10% of the global heating need in buildings – about half of what is needed in the NZE by 2030.
In some markets such as Japan and the European Union, and to some extent Korea, heat supplied from heat pumps is credited as renewable, making them eligible for support under certain renewable energy policy schemes. In 2022 China also recognised water and ground source heat pumps as a renewable energy technology at the national level, while in some provinces also air course units are included in the Green design standard of civil buildings.
Contribution of renewable electricity to heat pumps consumption in buildings space heating in the Net Zero Scenario, 2010-2030
OpenHeat pump sales decreased by around 3% globally in 2023
Heat pump sales decreased by around 3% globally in 2023
In Europe, in which the largest markets are France, Germany and Italy, sales declined by around 5% year-on-year, dropping to nearly 3 million units.
In the United States, sales of air-to-air units declined by 15% compared to the year before.
More heat pump units were sold in China in 2023 than in any other country, and China was the only major market where sales grew, at a robust 12%, as consumer activity recovered after Covid-19 restrictions were lifted. This growth was primarily driven by air-source heat pumps used for space heating, which experienced growth of over 15% year-on-year. In contrast, domestic hot water heat pumps remained at the same level as 2022. Around 35% of all heat pumps are manufactured in China, making the country the largest producer and exporter of this technology, with most of its exports going to Europe.
In Japan, heat pump water heaters sales were 10% down by end-2023, after having experienced 7 consecutive years of positive market growth (8% year-on-year on average), which neared 20% in 2022. Sales of air-to-air heat pumps saw as slight decline in 2023 as most units sold were to replace existing installations, which are typically one third less efficient than new models.
These negative market dynamics should be reverted to meet climate goals by 2050, as global sales need to expand by nearly 20% per year during this decade to align with the NZE Scenario.
Heat pump sales by country or region, 2019-2023
OpenGlobal manufacturing capacity will need to quadruple by 2030 to reach NZE Scenario targets
Global manufacturing capacity will need to quadruple by 2030 to reach NZE Scenario targets
Heat pump manufacturing capacity by announced projects in the Net Zero Scenario, 2022-2030
OpenIn 2022 and 2023, some of the major manufacturers, prevalently in Europe, announced expansion plans that – if realised in full – would increase global manufacturing capacity by more than one third. Announcements have slowed down in quantity and size over 2023, following the decrease of sales driven by policy uncertainties.
To get on track with deployment required in the NZE Scenario, existing global manufacturing capacity will need to almost quadruple by 2030.
However, manufacturing facilities can be deployed relatively quickly (one to three years); expansion projects are not widely announced, and therefore are not the only indicator on future expansion plans. Expansion to 2030 is therefore likely to be much greater than has currently been announced. Other barriers, such as shortages of installers, appear to be more pressing priorities for boosting heat pump deployment.
Innovation is key for heat pump deployment in more challenging market segments
Innovation is key for heat pump deployment in more challenging market segments
Heat pump performance has improved significantly over the last decades thanks to global R&D efforts and continued RD&D of heat pump technologies remains key to accelerating their deployment. Central ongoing innovation areas are:
- Enhanced heat pump systems for use in very cold climates, multi-family homes, large non-domestic buildings, high to very high heating temperature systems and existing buildings in general, as well as more compact solutions (see Climate and Comfort Box).
- Systems-oriented solutions such as algorithm design to optimise whole-building/district energy use, integrated active controls, integration with energy storage and thermal grids, on-site integration with solar PV and solar thermal, and control design.
- Climate-friendly refrigerants with very low or zero global warming potential .
- Improved acoustics and aesthetics to increase the acceptability and expand the installation potential.
- Innovative heat source techniques to reduce the surface footprint and cost of geothermal solutions such as deviated wells or to use heat from lakes, rivers and sewer systems.
- Heat pump solutions which recover waste heat from building ventilation or waste water.
A range of technology prizes help to recognise heat pump innovations and to scale up their deployment. Examples include the Peter Ritter von Rittinger International Heat Pump Award, the EHPA Heat Pump Award in Europe and the Residential Cold Climate Heat Pump Challenge in North America.
Heat pump patents share by inventor country, 2019-2020
OpenMore information
Accelerated heat pump deployment requires upgrades of supporting infrastructure, while automatised control systems can turn heat pumps into a grid asset
Accelerated heat pump deployment requires upgrades of supporting infrastructure, while automatised control systems can turn heat pumps into a grid asset
When heat pumps are installed in existing buildings with hydronic heat distribution systems, radiators may in some cases need to be replaced in order to allow the units to operate at lower temperatures, thus benefitting from greater efficiency.2 These upgrade costs can make up as much as a third of the total cost of installing a heat pump. Lower hydronic system temperatures can also be achieved by additional insulation of existing buildings and thus pave the way for higher heat pump efficiency. Financial incentives should therefore also address building and heat distribution system upgrades through holistically optimised renovation packages to enable heat pump deployment in existing buildings.
Meeting the increase in electricity demand from the accelerated deployment of heat pumps also requires investment to upgrade customer connections, distribution grids, generating capacity and flexibility. Heat pumps, combined with energy storage and active control systems, can absorb fluctuations from the increasing share of variable renewable energy such as wind or solar PV in electricity grids. For now, harnessing flexibility from heat pumps responsive to external signals from the grid and/or price signals remains a niche solution, though a number of pilot projects have successfully demonstrated the potential to reduce peak demand and remunerate customers for their contribution to lowering load.
2 Fossil fuel boilers generally operate with output temperatures at 60‐80°C. While heat pumps can produce heat above 55°C and potentially up to 70°C, their performance declines as their output temperature increases.
Policy support for heat pumps is increasing rapidly to meet decarbonisation and energy security ambitions
Policy support for heat pumps is increasing rapidly to meet decarbonisation and energy security ambitions
A range of policies have recently been introduced or strengthened to accelerate the deployment of heat pumps, in particular in Europe and North America in light of high natural gas prices as a result of Russia’s invasion of Ukraine, and efforts to reduce GHG emissions. Key policy instruments are:
- Heat pump deployment targets to provide confidence for the industry: Some European Union member states, as well as the United Kingdom, have announced ambitious deployment targets up to 2030.
- Financial incentives to reduce upfront costs: grants, income tax or VAT rebates and low-interest loans are currently available in over 30 countries around the world. Collectively, these countries make up more than 70% of global heating demand for buildings.
- Rebalanced energy taxation and heat pump tariffs to motivate fuel switching and account for flexibility: Some utilities offer specially metered electricity or special rates for consumers with electric heating, such as in Germany, where special rates reduce operating costs by 20% on average. The Dutch government aims to increase taxation of natural gas by up to 43% by 2026, while lowering taxation on clean heating fuels.
- Standards and labels for the deployment of efficient heat pumps: More than 45 countries have introduced mandatory labelling schemes and use mandatory standards to ensure minimum performance levels. In the United States, new heat pumps must meet more stringent efficiency requirements from 2023.
- Bans on fossil fuel technology installation to encourage clean heating alternatives: have been implemented or announced in more than 20 countries at the national or subnational level. In 2023 new bans came into effect in Austria, Slovenia and Flanders. Around 90 local governments in the United States require new homes to be exclusively powered by electricity for space and water heating, and other end uses.
Learn more
International cooperation is crucial to foster innovation and improve data on heat pumps
International cooperation is crucial to foster innovation and improve data on heat pumps
International collaboration supports knowledge and data sharing and generation, as well as accelerating standard harmonisation across countries.
The IEA Technology Collaboration Programme on Heat Pumping Technologies has been developing collaborative international research to innovate, demonstrate, collect and communicate advancements on heat pumping technologies since 1978.
The Mission Innovation Community on Affordable Heating and Cooling of Buildings aims to facilitate new partnerships, private investment and research collaboration to accelerate innovation in the sectors.
Stronger international collaboration on streamlining heat pump deployment data is also needed to inform policy decisions on accelerating the uptake of heat pumps.
Manufacturers are investing billions of dollars in expanding heat pump production capacities
Manufacturers are investing billions of dollars in expanding heat pump production capacities
As of mid 2024, manufacturers had announced more than USD 4 billion in expanding production capacity for heat pumps, their components and related efforts, mostly concentrated in Europe. Expanding production capacity by 2030 to the level outlined for that year in the NZE Scenario would require additional investments of USD 15 billion globally.
A growing number of manufacturers are also offering installation training programmes to address the shortage of installers.
In July 2023, Bosch announced the acquisition of Johnson Controls’ and Hitachi’s residential ventilation businesses for 8 USD billion, their largest-ever deal.
We would like to thank the following external reviewers:
We would like to thank the following external reviewers:
- Caroline Haglund Stignor, Monica Axell and Metkel Yebiyo - Heat Pump Centre
- Maurizio Pieve, Delegate Italy, HPT TCP
- Roger Hitchin, Alternate delegate UK, HPT TCP
- Wim Boydens, Alternate delegate Belgium, HPT TCP
- Francois Durier, Alternate delegate France, HPT TCP
- Viktor Ölen, Alternate delegate Sweden, HPT TCP
Recommendations
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Financial incentives such as grants, tax credits and low-interest loans are key tools to reduce the upfront costs of heat pumps, which often exceed those of fossil fuel powered heating systems. These measures should be designed to provide sufficient support for low-income households and address related costs for upgrades of heat distribution systems and other supporting infrastructure. Incentives for energy efficiency retrofits are also key to reduce overall energy demand in buildings, and operating costs for heat pumps installed in existing buildings.
Tilting energy taxation in favour of efficient electric heating can also increase cost competitiveness of heat pumps.
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Addressing restrictions or practical constraints for new installations and other barriers for consumers becomes even more pressing as upfront costs come down. One‐stop shops, for example, can inform consumers and help overcome administrative burdens.
In addition, building energy codes, Minimum Energy Performance Standards (MEPS) and labels can accelerate heat pump deployment, and – if regulations include requirements for metering and active control systems – can ensure flexibility for electricity systems. Bans on fossil fuel equipment as well as heat pump deployment targets can further provide a clear and stable long‐term vision to manufacturers and installers. Incorporating heat pumps into existing certifications for heating technicians, plumbers and electrical engineers would help tackle installer shortages.
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Increasing electrification requires the integration of national and local roadmaps on heating and cooling into traditional energy plans to co‑ordinate infrastructure development (e.g. electricity grid, district heat network, storage), optimise costs and tailor infrastructure adequately.
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RD&D can play an important role in the longer term to enhance the performance of heat pumps, in particular in cold climates, for buildings requiring high temperature distribution systems, and to exploit excess heat. A clear regulatory framework should also define responsibilities and financing models for the repair of heat pumps and the adequate recycling of their materials and refrigerants as more and more heat pumps reach their end of life.
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To be aligned with the Net Zero Emissions by 2050 Scenario, employment related to heat pumps has to more than double to 2030, with the most jobs in installation. Awareness campaigns and a proactive and strategic labour planning can play an important role to prevent shortages and bottlenecks.
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Heating- and cooling-as-a-service – renting out heat pumps to consumers and ensuring the proper operation of the technology – is a promising business model, with potential benefits both for consumers (relieving them from the high upfront cost challenge) and companies, which can benefit from more predictable and longer-lasting revenue flows than those associated with selling heating equipment.
Companies can also further exploit the synergies between different technologies by developing and selling integrated heat pump systems featuring metering, active demand response protocols, heat storage or even solar PV, as a package of appliances under one brand.
Heat pump operators can leverage the demand-side flexibility potential offered by heat pumps, for instance through dynamic electricity tariffs.
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More granular reporting on heat pump deployment by technology, capacity and building type, undertaken by industry associations in collaboration with national governments, will be crucial to ensure policy decisions on accelerating the uptake of heat pumps are well informed. Stronger international collaboration could facilitate the exchange of data collection and best practices, and the harmonisation of reporting. Knowledge sharing will be particularly valuable for experiments around electricity market designs (e.g. how to integrate demand-side response under specific electricity market regulation).
Programmes and partnerships
The Future of Heat Pumps
Heat pumps, powered by low-emissions electricity, are the central technology in the global transition to secure and sustainable heating.
Authors and contributors
Lead authors
Chiara Delmastro
Rafael Martinez-Gordon
Contributors
Francois Briens
Fabian Voswinkel