New Future Energy Scenarios and Clean Flexibility Roadmap: the future needs AD

In 2024, the last Future Energy Scenario (FES) produced by the then Electricity System Operator (ESO), which had formerly been a part of National Grid, came out and attempted to present credible paths to net zero for the UK. The 2024 FES was the first time when the National Energy System Operator (NESO) was meant to present the credible pathways to net zero with a statutory rather then informative manner and to deal with the whole energy system not just electricity generation.

At ADBA, we were frustrated by the 2024 FES that the models and scenarios completely ignored the role of biomethane in the energy system and simply treated the whole of gas distribution and gas fired electricity generation as a being fuelled by fossil gas.

Along with other sector advocates, these points were raised at the 2024 FES launch and reinforced through the year with the support of the other Green Gas Task Force members.

It was the NESO FES 2024 that primarily spawned the landmark ADBA report “The Role of Green Gas in Net Zero”. This was the first attempt that we are aware of to capture the full potential of biomethane and its ability to act as a carbon removal solution to the whole energy system not just a fossil gas substitute. Having worked intensely with Business Modelling Associates (BMA), we were able to launch our counter point to the FES at the end of 2024.

This was the report that demonstrated the potential of biomethane integrated into a whole energy system approach to reduce the cost of net zero by nearly £300bn. One of the major drivers behind this effort was the knowledge that the next FES update after 2025 would not be until 2028, which is far too late to integrate the vital understanding of AD and biomethane if it doesn’t come in 2025.

We discussed the biomethane question with the NESO throughout the beginning of 2025 and have been pleased by the positive engagement from them as an organisation. However, we were distinctly cautious about how this would transition to the FES 2025.

On 14 July 2025, the newly revised FES was released and the change is marked.

For the first time the FES features biomethane as a specific energy vector. This represents a major step forward and the changes are in line with, though not the same as, the findings in the December 2024 report from ADBA.

The new FES features four scenarios and a forecast based on current policies and positions. Of these scenarios, the most balanced one, “Holistic Transition” was the only one that met both the domestic, legally binding, carbon budgets and the international commitments under the Paris climate agreement in the form of Nationally Determined Contributions (NDCs). This “Holistic Transition” is the scenario that features the most biomethane at 36TWh in 2035, which enables meeting both the 6^th carbon budget and the NDC. This number is vital as it is virtually the same as what the DESNZ biomass strategy of 2023 suggested was available in 2050 for AD. Even more importantly the 2050 range in this scenario is based on minimum of 65TWh, this is less than ADBA and the GGTF believe is available but almost double what the 2023 biomass strategy assessed.

Importantly these estimates assume that the biomethane landscape is not limited to these numbers but that these are the minimum numbers needed to meet the decarbonisation requirements of the UK. This is a massively positive change that demonstrates the minimum value to the UK of biomethane.

On 23 July, the UK Government published the Clean Flexibility Roadmap – a publication aimed at showing how the UK can get renewable energy without needing to fall back on fossil-based backup generation. This was a collaboration between NESO, DESNZ and Ofgem. The flexibility roadmap is a massive shift for the government. Up to this point, the focus of biomethane has been on a domestic heat front, even though the ND-RHI and GGSS don’t explicitly buy the gas for that purpose but just top up the price into which ever GDN is hosting the injection. This roadmap for the first time makes the case in a government document that it is desirable to generate biomethane injected into the gas networks and use this for inter seasonal and peak balancing in existing gas turbine power plants. This is a case made in the 2024 ADBA report on the value of Green Gas in Net Zero.

This is the first time since the declaration of the Net Zero target that a clear, although so far slightly below the radar, vision for using biomethane to backup electricity generation, as well as industrial and domestic heat, has been made. This is the strongest indicator to date that the UK government is starting to take the potential of biomethane seriously. Taken in on the context of the recent inclusion of 65TWh of biomethane in the Future Energy Scenarios (FES) by the National Energy System Operator (NESO) shows that the UK is increasingly reaching the understanding that CP2030 and other decarbonisation targets need the support of AD to make these goals achievable.

However, both publications still fall short of the real potential, as neither of them take into account the potential for biomethane upgrading to do the highly efficient and very cost-effective job that it can, with this considered the sector becomes even more essential to meeting the decarbonisation needs of the UK at the most competitive cost. A 100TWh UK biomethane economy could capture 14Mt of CO2 per year, this is around 40% of the carbon removals that NESO forecast as essential for the UK to hit Net Zero in 2050. Given that the cost of CO2 capture from biomethane upgrading it around 1/5^th of the cost of post combustion CCS and the other system costs are the same, the AD sector presents a critical early block in building the future of the UK energy and carbon system. The UK CO2 transport and storage system can be supported with carbon removals from AD sites rather than expensive and highly subsidised CO2 from post combustion CCS on waste incinerators. As the climate is an accumulating system, the sooner these removals are brought into action the better. The recent news that the UK will look to integrate GGRs by 2029 is good, and we will analyse this response soon.

It is becoming clear that the UK government is starting to realise as we have, that there is no net zero without AD.