Wales & West Utilities (WWU) has launched an innovation project that could transform biomethane production by integrating low-carbon hydrogen into the process – increasing renewable gas yields and reducing operating costs.
Working with HydroStar, ENGIE and the University of Southampton, the project explores how injecting hydrogen during the acetogenesis stage – the point at which carbon dioxide is converted into biomethane – can enhance methane conversion efficiency. Early modelling indicates potential yield improvements of up to 70%, with system response times observed within minutes of hydrogen injection. This rapid reaction highlights the potential for anaerobic digestion (AD) plants to operate more dynamically, helping to balance peaks in energy demand in real time.
Biomethane – a renewable gas produced through AD – already plays a vital role in the UK’s low-carbon energy mix and is being injected into the gas grid to support national net zero goals. WWU has biomethane sites connected across its network, providing enough renewable gas into its pipeline to meet the annual gas demand of over 160,000 homes.
However, the biogas produced from most AD processes is only around 50% biomethane, with the remainder made up of carbon dioxide (CO2) and other impurities, which need to be stripped out before it enters the grid. WWU wants to explore whether hydrogen could help reduce the amount of CO2 produced in the process by turning more carbon into biomethane within the AD process.
The project’s detailed simulation model has been developed to assess how hydrogen injection affects biomethane yields and process stability. Information from this modelling shows promise and is shaping the design of a potential on-site demonstrator, which would aim to show that results can be delivered in real operational conditions.
For now, a small-scale demonstrator, scheduled to be operational in February 2026, hosted at one of ENGIE’s biomethane plants on WWU’s network, will validate the laboratory and modelling findings with support from the University of Southampton. The unit will enable detailed testing of hydrogen-enhanced biomethane production, confirming improvements in yield, response time and control strategies. The findings will demonstrate how existing AD infrastructure can be adapted to boost output and operational flexibility using low-carbon hydrogen.
Insights gained will also inform how the technology can be scaled to deliver more flexible, demand-responsive biomethane production across the network – strengthening energy resilience while supporting decarbonisation. Beyond the current project, the team hope to scale the technology up to full commercial scale using the data already developed and further learning anticipated.
Hannah O’Donnell, Net Zero Project Manager at Wales & West Utilities, said:
“Biomethane is a practical and scalable solution for decarbonising heat and power. By improving yields and reducing emissions, we can make better use of existing infrastructure and accelerate the UK’s journey to net zero.”
Charlie Newbold, Head of Operations at HydroStar, added:
“Beyond environmental benefits, the project will strengthen energy security by reducing reliance on imported fossil fuels, while stimulating rural economies through job creation and investment.
It also provides an important early-stage use case for hydrogen, supporting investment and innovation ahead of future regulatory change.”
The year-long project aims to make a significant step towards integrating low-carbon gases into the UK’s energy system and reinforces WWU’s commitment to delivering a reliable, resilient and sustainable energy future.