IGEM responds to Stonehaven’s Powering Homes, Powering Growth report
IGEM warmly welcomes today’s publication of Stonehaven’s report ‘Powering Homes, Powering Growth: A Practical Path to Heat Decarbonisation’, which offers a timely and insightful analysis of the challenges and opportunities facing the UK as we accelerate the transition to low-carbon heating.
Stonehaven’s research highlights the need for a more flexible, consumer-centred approach to heat decarbonisation, moving beyond a single-technology focus and embracing a diverse array of solutions, including bivalent and integrated hybrid heating systems, heat batteries and innovations yet to emerge. IGEM supports this outcome-based approach, which empowers consumers to choose the solutions best suited to their homes and circumstances, while unlocking a more affordable and resilient path to net zero.
Key messages from the report:
Flexibility over single technology focus
The report argues that the UK’s heat decarbonisation policy has been too narrowly focused on heat pumps, which has led to missed opportunities and high costs. Instead, it recommends a flexible, outcome-based approach that enables a range of technologies, including bivalent and integrated hybrid systems, heat batteries and future innovations to compete and deliver emissions reductions.
Consumer-centred policy
Stonehaven emphasises that policy should be designed around consumer needs and preferences, not just technical models. It highlights the importance of giving consumers real choice and control over how they decarbonise their homes, rather than mandating a single solution.
Cost and competition
The report notes that current plans relying heavily on heat pumps will require ongoing subsidies, the cumulative costs of which could cost the taxpayer up to £46bn by 2035, with 75% of homes still not converted. It calls for increased competition and market reform to drive down costs and improve consumer outcomes – noting that any further economies of scale are unlikely to deliver heat pump cost reductions that the Government wants to see happen by 2030.
System-level thinking
Stonehaven points out that decarbonising heat is not just about replacing boilers, but about rethinking the whole energy system – Including grid upgrades, energy storage and time-of-use tariffs – to make best use of renewables and minimise costs.
Gradual, pragmatic transition
The report advocates for a pragmatic, staged approach to decarbonisation that allows hybrid solutions to play a role, rather than insisting on full electrification or immediate heat pump adoption for all homes.
IGEM particularly welcomes the report’s recognition of hybrid heating systems, and the need for technology solutions to reflect the real-world diversity of UK housing stock. IGEM has long advocated for greater support for the deployment of hybrid heating systems as part of a range of technology options for consumers – a position echoed in a growing number of reports[1].
Importantly, such reports highlight how hybrid heating provides a pragmatic option for many consumers which minimises disruption and the need for significant behaviour change.
Other countries have been successfully leveraging hybrid heating innovation – for example, the UK showcased learning on hybrids from the Freedom Project in The Netherlands, as a globally leading example of innovative heat decarbonisation. Hybrid heating became the Dutch default heating installation, while the technology continued to be neglected in UK policy. Since then, The Netherlands have extended their hybrid technology away from their simple start to a smarter control system, akin to those first developed in the UK. They continue to install dense populations of hybrids, successfully managing electricity demand within subnetwork capacity limits as well as installing hybrids with hydrogen boilers.
The impact of hybrids on gas demand and bills is evident. The Association for Sustainable Heat (Vereniging voor Duurzame Warmte) in The Netherlands carried out a study on the impact of hybrids in 200 homes, over two winters. The research found that installing hybrid heat pumps in these homes (similar to UK housing stock) led to an average reduction in gas consumption of nearly 75% and households benefited from substantial energy cost savings, with annual bills dropping by around €1,000[2].
Hybrid heating has lacked any consistent policy support in the UK (having once qualified for the complex Renewable Heat Incentive option). This is despite the technology offering the opportunity to minimise system costs, improve heat pump deployment rates, relieve electricity grid constraints and make significant carbon savings – particularly with the growth of the biomethane market and the role that hydrogen can play in the gas network. Notably, Stonehaven point towards the uptake of hybrids being paired with policy to grow the volume of low carbon gas, like biomethane.
Stonehaven concludes that Government policy should reward any solution that delivers genuine emissions reductions. This approach would empower consumers to choose the most suitable heating solution for their homes, while fostering competition among suppliers to deliver cost-effective, reliable and low-carbon options. As their report shows (below), hybrid systems offer a lower operational fuel cost solution compared to a standalone heat pump or boiler, which still maintains a significant saving on emissions.
Stonehaven recommends reforming incentives and market mechanisms, such as revising the Clean Heat Market Mechanism (CHMM) to incentivise actual carbon reductions rather than just heat pump sales.
Recognising the need for significant investment in electricity networks and system flexibility, Stonehaven advocates for upgrades to support increased electrification and the integration of new heating technologies. Importantly, they emphasise the value of gradual decarbonisation pathways, allowing for partial and transitional solutions like hybrid heating systems to ease the shift for consumers and reduce upfront costs.
IGEM is actively working to support this agenda by championing the growth of biomethane and integration of hydrogen into the gas networks. Without these sustainable gases, consumer choices will be limited and our path to a decarbonised energy system will remain uncertain and constrained, undermining our ability to deliver affordable and practical low-carbon heat at scale.
We share Stonehaven’s view that the journey to net zero heat must be pragmatic, inclusive and responsive to consumer needs. IGEM remains committed to working with all stakeholders to deliver a decarbonised future that is affordable, reliable and fair.
We congratulate Stonehaven on this important contribution and look forward to continued collaboration as we move towards a cleaner, greener energy system.
[1] Talan (previously Gemserve), Unlocking the power of heat pumps with hybrid installations, November 2024; Cadent, The scope for using hybrid heating systems in home heating, April 2025; Guidehouse, Hybrid Heating Great Britain, November 2021; Watt-Logic, Heat Pumps, October 2024; Flexible Residential Energy Efficiency Demand Optimisation and Management (FREEDOM), Freedom Project Final Report, October 2018
[2] Hybrid heat pumps: A practical solution for lower energy bills, June 2025