Anaerobic digestion: achieving the 2020 vision

The Government has set it sights on an ambitious AD strategy over the next decade, but how will this be achieved? Steve Lee looks at the challenges involved

The Government has been signalling its desire to stimulate a much greater uptake of anaerobic digestion (AD) for some time, both in terms of its contribution to more sustainable waste management and a source of renewable energy. Earlier this year, Defra published Anaerobic Digestion – Shared Goals, with the overarching aim of making AD “an established technology in this country, making a significant and measurable contribution to our climate change and wider environmental objectives” by 2020. It put forward goals for various industry sectors as well local, regional and national government.

In moving forward to develop an implementation plan, a task group approach was adopted because of the range of sectors and stakeholders that needed to be represented and engaged. It has proved to be a good model, encouraging some very useful collaborative working and fostering a better understanding around the table of the different sectoral interests and issues. The model also recognised that although there are measures that government will need to take, many of the barriers to the uptake of AD need to be tackled by industry stakeholders.

Working within a very tight timeframe, the task group has come up with a list of 46 recommendations for practical action in both the short and medium term to support the development of AD and maximise the contribution it can make to diverting biodegradable waste from landfill, providing a viable source of renewable energy and reducing the CO2 footprint of agriculture and food production in England. In the process, several key issues emerged that will be fundamental to the achievement of the goals that have been set out.

Framework will be critical
Developing the right economic and policy framework will be critical. The various financial mechanisms – the renewables obligation, the proposed renewable heat incentive scheme and feed-in tariffs, the renewable transport fuel obligation and landfill tax to name but a few – all need to work together to deliver the best outcomes, both from an environmental and economic perspective. We need to ensure that each of the potential uses of biogas – i.e. locally or injected into the gas grid for heat and power and for transport fuel is incentivised, particularly for smaller scale projects – an area where AD offers significant opportunities.

Quality, both in terms of inputs and outputs, is another key factor in building long-term market confidence. Obtaining a regular supply of high quality feedstock will be important and food waste – both from household and commercial waste streams – has an important role to play in underpinning the viability of AD infrastructure moving forwards. The task group has recommended that the separate collection of household and commercial food waste should be supported and encouraged, with a particular focus on cost-effective collection. Accurate and ongoing mapping of food waste arisings and land bank availability is also needed to identify favourable locations for AD facilities.

A more complex challenge is the need to build confidence in the use of digestate as a fertiliser and soil conditioner. The task group has highlighted the need for the right information and data – both from existing best practice on other countries and through targeted UK-specific R&D – to improve our knowledge of the short and long term benefits of applying digestate to farm land. This information will lead to a better understanding within the farming community, help to inform the development of appropriate quality standards and application regimes, and build confidence in the food supply chain.

Action already underway
It is clear that there is a lot of work to be done, but what is encouraging is not only the level of positive support and interest that the task group encountered, but also the fact that some of the key issues are already being addressed. Changes to the exemptions and permitting regime that will help smaller scale AD plants in particular are underway, for example, and WRAP and the Environment Agency have produced a quality protocol for anaerobic digestate in consultation with industry that is now awaiting final ratification by the European Commission’s technical standards committee

It is also heartening to see that many of the necessary measures identified by the task group have been included in the Renewable Energy Strategy, including fine tuning the economic incentives, improving the planning process, adjusting the gas regulatory regime to help biomethane producers, developing standards for anaerobic digestate, and further funding for the anaerobic digestion demonstration programme.

There are also numerous references to AD throughout the 228-page UK Low Carbon Transition Plan and 236-page Renewable Energy Strategy which both came out on the same day as the task group report. It is good to note the strong links between these documents and that government, as well as the task group, believe that AD is a versatile technology with a recognised role in the UK’s effort to tackle climate change.

The next step is to get useful feedback on the recommendations that the task group has put forward. Input and commitments to action from all the relevant sectors will be important in the development of the implementation plan later this year, and we would urge interested stakeholders to contribute their views.

Steve Lee is chief executive officer of CIWM and chair of the AD task group

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