What the Shift to Biomethane Means for Existing CHP at AD Sites

As the UK continues its transition towards lower-carbon energy, biomethane is playing an increasingly important role, particularly for anaerobic digestion (AD) sites already operating combined heat and power (CHP) systems.

For operators with existing CHP assets, this shift raises some important questions. What does moving to biomethane mean for current CHP engines? Do systems need to change? And how does this affect long-term site strategy?

This blog explores what the growing focus on biomethane means in practical terms for CHP at AD sites.

Biomethane and AD: what’s changing?

Traditionally, many AD sites have used biogas directly in CHP systems to generate electricity and heat for on-site use or export. Increasingly, however, biomethane is being upgraded and injected into the gas grid, supported by government incentives and decarbonisation targets.

This doesn’t mean CHP is no longer relevant, but it does change how operators think about gas use, efficiency, and value.

Existing CHP systems can still play a role

For AD sites with CHP already installed, the move towards biomethane doesn’t automatically make those assets redundant. CHP systems remain a proven way to:

• Generate on-site electricity
• Meet continuous heat demand
• Improve overall fuel efficiency

In many cases, CHP can continue operating alongside biomethane upgrading, supporting site energy needs while maximising the value extracted from the gas produced.

Flexibility becomes more important

As AD sites evolve, flexibility is key. Decisions around how much gas is used on-site versus upgraded to biomethane will depend on factors such as:

• Heat demand on site
• Electricity prices
• Grid connection arrangements
• Support mechanisms and eligibility

CHP systems that can operate efficiently across different operating profiles help give operators more options as market and policy conditions change.

Efficiency still matters

One of the core benefits of CHP remains unchanged: efficiency. By using both the electrical and thermal output from gas, CHP systems extract more usable energy from each unit of fuel than separate generation.

Even as biomethane use increases, maintaining high efficiency on-site can help improve overall economics and reduce wasted energy.

Planning for the long term

For AD operators, the shift towards biomethane is less about replacing CHP and more about re-evaluating how CHP fits into a broader, long-term strategy.

Understanding how existing CHP assets can adapt, integrate, or continue delivering value alongside biomethane production is an important part of future planning, particularly as energy markets and policy frameworks continue to evolve.

If you’d like to understand what the shift to biomethane could mean for your existing CHP system, our sales team can provide tailored support.

Call 01928 718533 or email sales@2-g.com