The Green Gas Taskforce (GGT) has published a report on Bio-Hybrid heating, produced in partnership with Cadent and working with the consultancy Guidehouse, assessing the role biomethane-fuelled boilers combined with air source heat pumps could play in decarbonising heat1. The report, Green Gas Homes: Bio-Hybrids: A Clean Heat Solution, was presented in the context of the All-Party Parliamentary Group for Energy Studies' annual Winter Warmer reception at the House of Commons, sponsored by Future Energy Networks and the GGT1.
Its analysis suggests Bio-Hybrid systems are the lowest-cost clean heat option for between 30 percent and 45 percent of homes today, particularly properties with EPC ratings of D, E or F, which are typically harder to decarbonise1. IGEM's response to the Department for Energy Security and Net Zero consultation on alternative clean heating solutions states that bio-hybrids provide the lowest cost clean heating option for between 30 and 45 percent of GB households, and that biomethane-fuelled boilers used with electric heat pumps can deliver emissions cuts of 90 to 95 percent today and close to 100 percent by 2050 in low-to-moderate efficiency buildings2.
Hybrid systems typically use a heat pump in milder conditions or when electricity prices are lower, retaining a boiler for peak demand and hot water, with smart controls switching between electricity and gas; when biomethane replaces natural gas the system becomes fully decarbonised1. IGEM states that today's biomethane output is sufficient to heat around one million homes, and that when paired with hybrid systems the same volume can decarbonise up to five million2. It adds that the UK could sustainably produce up to 50 TWh of biomethane per annum by 2030, rising to 120 TWh by 2050, of which up to around 40 TWh can serve residential heating demand2.
Polling conducted alongside the report found that when asked how they would spend £8,640, roughly equivalent to four years of typical savings and the approximate cost of upgrading an EPC D property to EPC C, only 11 percent of respondents mentioned home improvements at all, with holidays and travel ranking highest1. On home insulation specifically, 45 percent said they would not spend anything, a further 24 percent said they could not because they rent their property, and only 2 percent said they would be willing to spend the full amount required1.
"Its analysis suggests Bio-Hybrid systems are the lowest-cost clean heat option for between 30 percent and 45 percent of homes today"
The report follows publication of the Warm Homes Plan in January, which IGEM says focuses mainly on fully electric heat pumps working with solar PV, and resets the heat pump installation target to 450,000 per year by 2030 from an earlier 600,000 by 20281. IGEM states that a subsidy of the scale of £7,500 is needed per heat pump installation under the Boiler Upgrade Scheme, and that government has expanded the scheme to include technologies such as heat batteries and air-to-air heat pumps, while hybrid heat pumps remain absent1. IGEM's consultation response notes that green gas compatible hybrid heating is not currently supported within most current UK heating policies2.
| Measure | Figure |
|---|---|
| Homes where Bio-Hybrids are lowest-cost clean heat option | 30 to 45 percent1 |
| Emissions cuts from biomethane boilers with heat pumps, today | 90 to 95 percent2 |
| Emissions cuts by 2050, low-to-moderate efficiency buildings | Close to 100 percent2 |
| UK sustainable biomethane potential by 2030 | Up to 50 TWh per annum2 |
| UK sustainable biomethane potential by 2050 | 120 TWh per annum2 |
| Dutch trial gas demand reduction | Around 75 percent2 |
| Dutch trial bill reduction | Around £650 per year2 |
Why it matters for households
For homes that are expensive or technically difficult to electrify fully, the report's central claim is that a hybrid system can lower costs by reducing the need for extensive upgrades often required for a fully electric heat pump installation, such as radiator replacements or pipework changes, and can provide a pathway for households with existing combi boilers1. IGEM states that hybrid systems avoid disruptive fabric upgrades such as hot water storage tanks, larger capacity radiators and larger diameter pipework, reduce upfront costs relative to full electrification, and reduce household bills through lower gas consumption2. It also states that hybrid systems shift load away from peak periods using the gas vector, reduce the need for network reinforcement and improve system resilience in cold weather2. The emerging-tech hub covers related technologies, including whether heat batteries could become eligible for the Boiler Upgrade Scheme, and how a hydrogen boiler compares with a natural gas boiler.
What happens next
IGEM encourages DESNZ to integrate these solutions into forthcoming policy developments2. The consultation on alternative clean heating solutions has closed; no decision on its outcome has been reported.