The Energy Research Accelerator and the University of Nottingham hosted the second Decarbonising UK Domestic Heating: Disruptive Approaches event on 21 November 2025 at the IMechE headquarters in Westminster. It brought together academics, industry leaders and policymakers to discuss real-world decarbonisation projects and innovative ideas that could accelerate the transition to zero-carbon heating.
Antonia Mattos, head of energy research at the Department of Energy Security and Net Zero, chaired the event, highlighting government initiatives including the Boiler Upgrade Scheme, heat network zoning and the Heat Pump Investment Accelerator to support the supply chain. The UK’s carbon budget and growth delivery plan provide a flexible roadmap for heat decarbonisation, she said, supported by £42m in market preparation investment for heat pumps.
Throughout the day, 18 experts shared insights on three main themes: electric heat pumps and district heat networks; heat batteries and emerging technologies; and hydrogen. Professor Chris Jones from the University of Portsmouth opened with a keynote on social acceptance, noting that public attitudes significantly influence the adoption of heat pumps in urban housing. Adoption barriers include high upfront costs, disruption, aesthetic concerns and lack of awareness.
Surveys indicate that younger people are more receptive to new technologies, especially when exposed to immersive, informative content, while older populations prefer familiar systems. Social acceptance must be integrated into technology design, with collaboration between social scientists and engineers to overcome behavioural and societal barriers.
Under pressure
A key session focused on the GasNetNew project, a three-year initiative funded by the Engineering and Physical Sciences Research Council to explore future uses for the gas network beyond hydrogen. Professor Grant Wilson of the University of Birmingham highlighted that the UK gas network already serves as a vast, de facto energy storage system through “line pack”, where gas stored under pressure in pipelines effectively stores and releases energy. Local distribution alone holds around 600GWh – roughly 9-10kWh per household during the heating season – smoothing daily demand peaks.
This storage is largely unvalued in current accounting, however, raising questions about pricing and system integration. Replacing gas without maintaining its flexibility could be costly and destabilising.
Ice source heat pumps, which repurpose existing gas pipelines to circulate water and extract heat by partially freezing it, were presented by Dr Ramin Mehdipour from the University of Nottingham. The approach could offer stable, efficient performance in cold weather, compact indoor installation, low water use and the potential to reuse existing infrastructure. Challenges such as ice disposal, peak demand management and seasonal performance are under investigation, but lab prototypes reportedly show strong commercial potential.
Domestic thermal energy storage was discussed by Dr Ed Barbour from the University of Birmingham, demonstrating that modest storage – around 10kWh, equivalent to a 200-litre hot water tank – can reduce peak electricity demand for heating by about 30%. Larger storage can smooth peaks further, but also increases total electricity use if charged resistively. Thermal storage enables smaller, more efficient heat pumps and offers a cost-effective way to manage peak demand.
Electrification of heat
Consumer experience is key when deploying low-carbon heating, said Kat Young from the Energy Systems Catapult. In its Electrification of Heat Demonstration Project, 742 heat pumps were installed, with 85% of participants recommending them. Installation disruption and variable performance highlighted the need for high-quality design, installation and guidance.
Current retrofit trials focus on low-cost insulation and air-to-air heat pumps for flats, and compact heat batteries, which minimise disruption. Flats, however, face additional challenges such as noise limits, planning requirements and leaseholder consent, making communal networks or shared solutions often more practical.
Ground source heat pumps offer low-carbon, reliable and cost-effective heating with minimal maintenance despite high upfront costs and installation disruption, according to Wouter Thijssen from Kensa, who outlined their potential in high-density, older UK housing. Kensa provides service to 81 flats using roughly 7,000 boreholes, which can be scaled for district heating, integrating waste or PV-generated heat to reduce grid stress and enable mass deployment.
An ambitious heat network in Bristol is serving central areas, supplying energy to new builds, retrofits and complex sites such as Victorian schools, as described by John Sankey from Vattenfall. Supported by policies requiring new developments to connect or be future-ready, innovative projects include integrating heat from computing at the Quantum and AI centre, and plans to connect large-scale waste heat to support future developments of up to 40,000 homes.
The network reportedly reduces peak electricity demand, improves grid efficiency, offers competitive costs and aims to provide heat to over half of Bristol’s population by 2050.
Dr Joel Hamilton from Translating Energy stressed the critical role of buildings in UK carbon emissions, with 85% of homes heated by gas. Achieving net zero by 2050 will require retrofitting most existing homes with a combination of electrification, biofuels, hydrogen and waste heat solutions, he said.
Heat networks and thermal storage can smooth peak demand and integrate intermittent renewables, but only 3% of heat demand is currently covered by networks, which could rise to 20% by 2050. Waste heat from power stations, incinerators and supermarkets could reportedly supply 282TWh/year, generating economic savings – but success will rely on effective engagement with government, industry and the public.
Aqua ammonia heat pumps
A compact, flexible heat battery storing 40kWh of ultra-high-density thermal energy at up to 800°C was introduced by Johan du Plessis from Tepeo. The Zero Emission Boiler integrates with existing radiators or underfloor systems, he explained, predicting household demand, purchasing low-cost electricity and supporting off-peak consumption and grid stability. Competitive with air source heat pumps, it could offer low running costs, long lifespan and compatibility with government schemes like the Boiler Upgrade Scheme.
Aqua ammonia heat pumps were presented by Dr Rosa Baniamerian from the University of Nottingham. The technology uses ammonia dissolved in water and can work with existing gas pipelines. The system provides high-temperature water, reduces reliance on new infrastructure and suits dense urban areas, Baniamerian said. Successful adoption would require policy support, public engagement and integration with existing networks.
Fixing the ‘spark gap’
The event concluded with a panel discussion featuring industry leaders from Northern Gas Networks, Vaillant UK, Kiwa, Octopus Energy and Baxi. Drawing from international experience, panellists emphasised the importance of policy stability, cautioning against sudden subsidy changes that disrupt markets. Households prioritise comfort, reliability and cost over technology, they said, and older homes and flats present practical barriers.
Trade-offs will have to be made between low-temperature, high-efficiency systems that require upgrades and high-temperature systems that reduce disruption but may cost more to run, panellists said. Mandating specific technologies without consumer buy-in could risk backlash, while ‘zero-bills homes’ combining photovoltaic cells, batteries and heat pumps remain limited by winter solar availability and infrastructure costs.
Hydrogen was debated as a potential solution for seasonal storage, using existing gas infrastructure, though concerns remain over cost, leakage and policy uncertainty. Addressing three points could accelerate progress, however, the panellists concluded:
- Fix the ‘spark gap’: Reduce electricity prices relative to gas to make heat pumps affordable to run.
- Policy stability and clarity: Stop speculative or inconsistent policy signals that undermine investment.
- Recognition of system needs: Include seasonal storage and peak demand, whether through hydrogen, networks or other solutions.
Overall, the event highlighted the technical, social and policy complexities of decarbonising heat. It showed that solutions need to be consumer-focused, flexible and cost-effective, drawing on a combination of electrification, heat networks, thermal storage, emerging technologies and potentially hydrogen. Effective collaboration across government, industry, academia and the public will be critical to achieving a low-carbon, reliable and equitable heating transition.
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