I joined Future Biogas in July 2019 as the 4th year of my degree involves spending a year in industry before I return in September 2020 to complete my master’s in chemical engineering at the University of Sheffield.

I have been incredibly lucky with my experiences at Future Biogas (FB) as I have been given great flexibility to spend time with different departments and absorb some of the knowledge of the masterminds behind the business.

Autumn is a busy time for anaerobic digestion (AD) plants across the UK as crops such as Maize are harvested and transported to be ensiled in clamps. For me, the closest exposure I had to agriculture prior to this were the many years that I spent ‘beating’ with my father and brother in Surrey (although, cover crops, in shooting terms, have a slightly different meaning).

Farming was, therefore, always one of those unassuming sectors that ticked away in the background but to which I had limited exposure. In September last 2019, I was given the opportunity to spend time in Norfolk, at Redstow Renewables, a 4.5 MW (megawatt) AD plant in Swaffham that supplies electricity to RAF Marham. During that week I got a sense of the true grit of farmers and how tirelessly they work. I often relate this to the Toyota Hilux that featured on that famous Top Gear episode that still turned over after having everything thrown at it. I distinctly remember being sat in a behemoth of a machine known as a forager that churned through Maize like butter whilst the operator loaded the trailer behind so elegantly. Behind was another trailer that had offloaded at site and returned to the field in time to create a harmonious production line that continued from the early hours until late at night. I remember vividly being told to look under my seat if I wanted anything to eat or drink only to discover my seat was concealing a medium sized fridge. The offerings were only second to that of the biscuit tin (and draws) at FB, which are extensive to say the least! I was hardly surprised, as sitting in the forager is how I imagine the air traffic control tower at Heathrow to look like.

View from a forager

Another aspect that I have enjoyed during the year were the numerous conferences that I have been able to attend such as the Energy expo, REA and the ADBA national conference. These have really given great insight into the future for AD and where the barriers are for future investment. This led perfectly into the first discussion group set up by Helen Wyman, for Fern AD and Farming, a subsidiary consultancy service launched in April 2020. The conception of the group was driven by the ethos that accrued company knowledge across the sector must be shared, and only in collaboration within the renewable energy industry will we be able to achieve net zero.

Future Biogas run a portfolio of 13 anaerobic digestion plants and one of the reasons why I think it has been so successful and a key knowledge resource for the industry is through its implementation of vertical integration. All of the sites have their biology meticulously monitored by the labs in Guildford which help to optimise and maintain the microbiology within the digesters. Furthermore, FB have a team of extremely talented maintenance engineers that keep the sites running optimally and, crucially, applying lessons learned to other sites when they undergo works.

Despite the Covid-19 pandemic bringing the world to an abrupt halt and changing our way of life, efforts toward decarbonisation must be incorporated into the global economic and social rebound. We must not return to business as usual and we must instead pursue clean growth. One overwhelming conclusion from my internship so far is that agriculture is very much integral to a net zero solution. In addition, one could argue that soil is our most important resource whilst also storing a tremendous amount of carbon. However, whilst we may be driving efficiency and yields from crops, overuse of synthetic fertilisers, monocropping, excessive tillage and reduced cover crop use can be detrimental. In a lot of cases, without stringent practices/standards and behavioural shifts we risk degrading soils and failing to address the significant carbon footprint of the sector. This may seem negative but the downfall is largely due to the untapped potential of agricultural practices that build soil carbon, maximise crop resilience, nutrient density and biodiversity thus, failing to recognise that agriculture also provides a significant carbon sink. Anaerobic digestion is a solution that offers a way of introducing these regenerative agricultural practices.

There seems to be a general lack of confidence in crop fed AD outside the industry. One example of this is the mandatory waste-quota in RHI (Renewable Heat Incentive) and double credits awarded for waste under the RTFO (Renewable Transport Fuel Obligation). The use of AD has far reaching benefits, providing farmers with a stable income and guarding against commodity market fluctuations – much the same as the current incentive for renewable energy investment, given the recent oil price fluctuations. Moreover, energy crops should be part of a rotation and not considered to be grown instead of food, as this is necessary to optimise crop yields and the soil ecosystem. This conclusion is very topical and poses a threat to further government financial support unless it is debunked. Digestate from AD does not build or maintain soil carbon and can replace the use of artificial fertiliser, which is produced industrially and with a significant carbon footprint. Finally, the ability to utilise waste feedstocks reduces the use of landfill and investment into the industry results in local value creation which is critical for a successful economic recovery.

More broadly speaking, AD’s trump card is the ability to use the existing gas infrastructure in the UK and displace fossil fuel with green gas. Whilst renewable electricity is becoming increasingly more price competitive, if we were to electrify heat, the demand for electricity would be exorbitant. There are also other sectors such as transport and agriculture which are harder to abate and which cannot achieve carbon neutrality without green gas.

I believe the next chapter for AD will be the role of an increasing carbon tax, the introduction of mandatory food waste collection in 2023, developments in carbon capture and the growing pressures from businesses and the public to reduce their carbon footprint. Through no fault of its own, the AD sector seems to suffer from an over reliance of government subsidies to build a business case, such as payment through the RHI and FiT (Feed-in Tariff). It is no surprise that AD deployment has recently tailed off due to decreasing support; this will hopefully be re-incentivised by the new green gas support scheme from BEIS (Department for Business, Energy & Industrial Strategy). However, is there a future for subsidy free-AD?

One idea is the growth of the rural economy and how farmers or landowners could benefit from additional revenues such as carbon trading. This would involve being paid for regenerative agricultural practices and afforestation, key for businesses that have hard to abate emissions or those looking to offset their scope 3 emissions. This idea also links to the already growing market for green gas certificates sold through the GGT (Green Gas Trading) and GGCS (Green Gas Certification Scheme) that can only be forecasted to increase in demand.

Carbon alone is a topic in itself and offers many opportunities for further deployment of AD:

  • Increasing carbon taxes will make the business case for biomethane injection more appealing against fossil gas although, not fully utilising AD could just increase energy prices across the board.
  • The growth of CNG (compressed natural gas) vehicles in the HGV (heavy good vehicle) sector being paid under the RTFO.
  • The capture of carbon from an AD plant being sequestered or permanently embedded in building materials through BECCS (Bioenergy with Carbon Capture and Storage), to create negative carbon factories.
  • Carbon being captured and used to create synthetic aviation fuels when combined with green hydrogen in the Fischer-Tropsch process.

Overall, I think AD has a very exciting future and deserves more recognition for its circular nature. The ability to provide green gas and utilise the waste products to protect our most valuable resource and sequester carbon.

I also want to take this opportunity to sincerely thank everyone at Future Biogas that I have had the pleasure of spending time with and learning so much from. The team really go above and beyond and never fail to upkeep the family atmosphere even in the hard times we face. It is the time that everyone has invested in me which has made the experience so invaluable. I have never been more confident about my future career and it is all thanks to the foundations formed at Future Biogas that have been second to none.

Thank you for reading.

Alex Payne

Project Engineering Intern