The fossil fuel era is over. It is now a matter of logistics. Many potential pathways exist to decarbonise energy, yet we do not have time for trial and error.

Grange Farm Anaerobic Digestion Plant

Green Gas is the Future

As the largest producer of biomethane in the UK, we believe renewable gasses are a crucial element to the energy revolution. This is especially true for those sectors difficult to decarbonise such as heating and transport – which biomethane is particularly well suited to decarbonise. While it is possible to electrify much of our energy use, comparisons of balanced scenarios (balancing gas and electricity) vs mostly electrified scenarios indicate that by far the cheapest pathway to net neutral emissions is turning our gas green. As such, we were delighted to hear the Government’s decision to support biomethane from AD in their new Green Gas Support Scheme (GGSS), a new subsidy system designed to increase the proportion of green gas in the grid.

Underestimating the Potential of Biomethane

We were hoping the new scheme would improve upon the current system, the Renewable Heat Incentive (RHI). Tariff degressions and the RHI’s looming termination, scheduled for March 2021, has created much uncertainty in the AD sector. After around a decade of growth, our industry has plateaued. In 2019, approximately 3.6 Tera-Watt-hours of biogas from AD were injected into the national gas grid. – enough to provide heating for just under 280,000 homes. This accounts for under 1% of the UK’s natural gas use.


Biomethane has so much more to offer than this. Industry and independent bodies have conducted reports predicting the potential scale of UK biogas production from AD for heating and transport. Both trade associations that represent the AD industry calculate a contribution of over 50 TWh by 2032 (REA, 2019; ADBA, 2020), while research prepared for the Energy Network Association suggests over 50TWh by 2050. The Committee on Climate Change, the government appointed advisory body on emissions targets, has set a goal a goal of 20  Terawatt-hours per year by 2030 – on heating alone.


The proposed annual target from BEIS under the GGSS would increase the biomethane injected to the grid by 2.4 Terawatt-hours per year by 2030/2031. Under the RHI (including new applications) and the GGSS contribution, the REA estimate ~9TWh/annum of biomethane from AD by 2026. While the figures from ADBA, the REA and ENA include transport as well as heat, the Government are still far off independent predictions – including the CCC. Our industry needs the right government backing to fulfil its potential. We had hoped the GGSS would provide just that. However, in this format, it seriously downplays biomethane’s potential contribution to attaining net zero.

Feedstocks

The discrepancy between Government and industry figures boils down to feedstocks, the materials used to make raw biogas. The GGSS is based solely upon food waste from municipal sources – ignoring not only agricultural wastes, like manures and slurries, but also the vast potential of specially-grown energy crops.

Agricultural waste

Whilst we unreservedly support plans to turn food waste from homes, public institutions and the hospitality sector into renewable energy, we do not believe that it should be the GGSS’ sole focus. Each year, around 83 million tonnes of manures and slurries are produced by livestock in the UK. Data from 2018 suggests that only 3% of farms use AD to process them and yet the best way to stop such farm wastes releasing CO2 into the atmosphere is to use them as a feedstock in the AD process. That way, their potentially dangerous emissions become renewable energy. It’s a win-win.

Regenerative Crops

Leaving out purpose-grown energy crops is another serious omission. When grown as part of a farming rotation with food crops, they not only optimise the AD process and biogas yields but also offer a unique range of further benefits in terms of farming sustainability.

Maize grown within a crop rotation

Crucially, they can create a circular food-fuel agricultural system that addresses one of the gravest environmental threats of all: the ongoing degradation of our soils. After crops have been used to make gas, the leftover sludge in the tank – known as ‘digestate’ – can be applied to fields as a natural fertiliser. Not only does this reduce the need for harmful chemical-based fertilisers, but it also means the remnants of the previous crop are used to boost the next one and improve the soil’s organic matter. Case studies in Europe (see Biogas Done Right) are already showing significant savings in GHG emissions; increased yields of primary food crops and reduced soil erosion all through adopting alternative farming practices with AD.

Investing in biogas’ potential

Of course, we welcome all investment in the AD sector, and we appreciate the intent of this scheme. However, this is a significant moment in the climate crisis. We must make the right decisions, and we must make them quickly. To hit net zero on time, we have got to be as efficient and streamlined as possible. If this scheme is brought into existence, we can only hope that it will be based upon AD’s true potential. Too much is at stake for this opportunity to be wasted.

Written by Finn Boykew, Policy Advisor, Future Biogas

Edited by Melissa @ThatDot