Biomethane, hybrid heating and the real cost of net zero

New analysis commissioned by the Institution of Gas Engineers & Managers (IGEM) and carried out by Imperial College London shows that scaling up sustainable biomethane and adopting hybrid heating systems could significantly reduce the overall cost of delivering a net zero energy system in Great Britain.

The research, Role and value of biomethane in supporting the 2050 GB net‑zero energy system, examines whole‑system costs and energy balances across multiple pathways to net zero using Imperial College London’s integrated gas/hydrogen and electricity system (IHES) model. It compares deep electrification of heat with hybrid heat pump pathways under different levels of biomethane deployment.

Across all scenarios assessed, increasing biomethane supply reduces total annualised system costs. By 2050, moving from no biomethane to high biomethane availability (120 TWh) reduces whole‑system costs by approximately £4–6 billion per year, reflecting lower reliance on higher‑cost energy supply and carbon removal options.

The lowest overall system costs are achieved in pathways that combine higher levels of biomethane with hybrid heating systems as a compounded benefit. In these cases, total annual system costs are up to £5.5 billion per year lower than under full electrification of heat, equivalent to an almost 8% reduction compared with electrified pathways without biomethane.

Hybrid pathways reduce electricity demand by retaining a role for low‑carbon gas in meeting heat demand, lowering the need for additional electricity generation, network reinforcement and nuclear investment. At the same time, higher biomethane availability reduces the operating costs of the hydrogen system and limits the scale of hydrogen production through biomass gasification with carbon capture and storage (BECCS) required to offset residual emissions.

The study also highlights the strategic system value of gas infrastructure. Under hybrid pathways, gas networks continue to play a substantial role in supplying heat, industry and power generation, with biomethane increasingly transported through existing pipelines as a cost‑effective low‑carbon fuel. This strengthens security of supply by reducing import dependency and enhances system resilience through the use of gas storage and linepack.

Commenting on the findings, Oliver Lancaster, Chief Executive Officer of IGEM, said:

“The critical issue for net zero is system cost, because that ultimately feeds through to consumer bills. This analysis shows that moving too quickly to a fully electrified system can increase costs. A more pragmatic transition which maximises sustainable biomethane, supports hybrid heating in homes and uses hydrogen in industrial clusters, can reduce import dependency and deliver lower system costs year on year, while still achieving net zero.”

The results are consistent with national energy system modelling, including NESO’s Future Energy Scenarios 2025, which indicate that gas networks persist across all net zero pathways. The analysis shows that biomethane availability, rising from today’s levels of around 7 TWh per year to at least 64 TWh per year by 2050, and potentially higher within sustainability constraints, is a key driver of improved affordability and resilience in the energy transition.

Dr Hossein Ameli, Advanced Research Fellow at Imperial College London, mentioned:

“The findings demonstrate that sustainable biomethane is not simply a supplementary option, but a strategic lever for reducing the cost of net zero. Higher biomethane availability lowers annual system costs under both heat pathways, while hybrid heating systems that retain the value of existing gas networks outperform full electrification in cost terms. This underlines the importance of supporting biomethane scale-up as part of a pragmatic and affordable route to decarbonisation.”

Furthermore, Professor Goran Strbac, Chair in Electrical Energy Systems at Imperial College London added that:

“Our results show clear potential for biomethane, but they also underline that its system value is highly dependent on the wider context in which it is deployed. Technology costs, network constraints, gas network transition pathways, and the cost of heat electrification can all materially change both the scale and direction of the benefits. A policy-grade assessment therefore requires systematic sensitivity analysis to identify under what policy and network conditions biomethane’s value can be unlocked, and how the gas system itself, including linepack, can contribute to resilience during extreme weather and rare events.”