Anaerobic digestion (AD) can be a fundamental part of Irish agriculture, like it is elsewhere in Europe, but obstacles still stand in its path. This was a key message at the recent conference on biomethane in Birr, Offaly. The conference was organised by the community group Birr 20:20 Vision, with the help of Nephin Renewable Gas. The Irish Farmers Journal went along to the event.

The conference kicked off with an opening address by group chair Sean Loughnane, who likened the challenge of AD to completing a jigsaw puzzle.

“We’re all responsible for different parts of this jigsaw, including the Government, regulators, licensees, developers, financiers, and farmers,” he said. This was a sentiment echoed in a speech by Professor John Feehan, who urged attendees to grasp the nettle of climate change

Need to adapt

The morning session was chaired by Jackie Cahill TD, who said that farmers recognise the need to adapt. He said he was confident in farmers’ ability to rise to the challenge and highlighted the economic opportunity associated with AD for farmers, saying that it could become a viable income source for farmers.

As part of Ireland’s commitments in its Climate Action Plan, the country must develop approximately 150-200 large-scale AD plants to produce 5.7TWh of biomethane by 2030.

Addressing emissions reduction and water quality issues facing agriculture, he said that AD would play a crucial role in addressing these issues, and allowing farmers to produce food sustainably.

Not just gas

Jerry Murphy, director of the SFI MaREI Centre and a seasoned AD researcher and advocate, expanded on the wider opportunities that the establishment of an AD industry would present. At its most fundamental level, an AD plant produces renewable gas from feedstock. The focus of the Irish industry is to use agricultural feedstock due to its sheer abundance. According to Professor Murphy, the potential for biomethane production using on-farm resources like slurries and manures is high, equivalent to 200% of the entire gas consumption of Ireland.

However, once the AD industry is established, many other processes are possible. These include the extraction of valuable ingredients from feedstock for industry, either before or after digestion, to the potential to introduce hydrogen into the AD process to significantly increase methane production, to the production of microalgae in a biorefinery integrated with an AD plant. The potential avenues for innovation are massive, once the industry is established.


Graeme Lochhead, commercial director at Nephin Renewable Gas, a recently established biomethane firm headquartered in Tipperary, gave a rundown of feedstock options for AD plants. Nephin is aiming to develop approximately 30 AD plants around Ireland. The initial three AD plants are set to be submitted for planning by April, with two more planned for later in the year, and the first gas production expected in 2025.

Each AD plant will require approximately 60,000-70,000t of feedstock, with a significant portion sourced from farmers. Graeme explained that this presents an opportunity for farmers to secure long-term contracts for supplying these plants, generating new revenue streams by supplying animal manures, slurries, grass silage and crops.

Graeme explains that each plant will support 70-75 jobs in rural areas, while also safeguarding existing employment within the farming sector. While the AD industry in Ireland won’t solely rely on crops, they will play a central role. According to Graeme, grass silage and, especially, wholecrop hybrid rye, are expected to be significant crops for their plants. Wholecrop cereals are a more suitable choice for Ireland compared to maize, due to their earlier harvesting dates.


The challenges with securing planning permission were a constant theme throughout the conference, and I had the opportunity to speak about my own experiences with the planning system with a community AD project in Donegal I am involved with. It wouldn’t be an overstatement to say that the entire process is incredibly challenging.

Oísin Doherty, technical lead for biogas at the planning consultancy firm ORS, shed some light on the intricacies of a planning application. When submitting a planning application for an AD plant, numerous factors must be considered, many of which are site-specific. Elements such as noise, odour, air quality, traffic and access, landscape and visual impact, zoning regulations and the need for EPA licenses, are all evaluated within the application.

Oísin stressed the importance of understanding the lead time required for a project. He has successfully managed a planning application for an AD plant in Carnaross, Co Meath, which served as a useful example. For a plant of similar size, processing over 50,000t of feedstock annually, he outlined the project timelines.

He explained that many developers start with a feasibility study, which can take up to three months. The phases involving plant design and public consultation may take another three to six months, followed by the preparation of the planning application and associated environmental reports, which could take an additional three to six months. Once the application is submitted, it typically takes two months for the local authority to assess it. Usually, a request for additional information is made, which could add one to two months, followed by another two months for the local authority to evaluate the responses.

A decision is then made, and there is a one-month window to appeal it. So, the entire process takes 14-21 months for an application to be processed. If the decision is appealed or faces further challenges, this timeline could easily double. Furthermore, for AD plants requiring an EPA industrial emission licence or waste licence, which now appears likely that they will be all plants, an extra 12-18 months must be factored in, extending the timeline to four years. Though the cost of planning wasn’t discussed, it’s worth noting that applications for projects like these can likely exceed €300,000, with no guarantee of being granted panning.

Many felt the further education of local authority planners and regulators was needed in the areas of AD, development, licensing and operation. John Perry, the principal of Gurteen Agricultural College, stated that his programme aimed to fulfil this requirement for students who would become the future decision-makers in farming.

Water quality

Teagasc’s Edward Burgess, emphasised the importance of adhering to the fundamental principles of good nutrient management to prevent digestate from becoming a potential issue for water quality. It was stressed that having sufficient storage capacity is essential to ensure the digestate is used when crops are actually growing. However, it was also noted that digestate, with its higher nutrient availability, may have the potential to be transported further than conventional slurry. This means it could be transported to areas where these nutrients are needed, a particular advantage for intensive livestock areas.

Community engagement

Minister Pippa Hackett chaired the afternoon session and stressed the need to get the delayed Biomethane Strategy right, hence why it was sent for public consultation. She also emphasised the need for community engagement in AD projects.

Dr Deirdre Lewis, from SLR Consulting, spoke at the conference and discussed the challenge of community engagement. Often communities are asked to accept projects they may not want, and this is especially the case when it comes to AD. To gain community support, it’s crucial to engage from the very beginning and show the need for the project in the area. The developer must understand the local issues and history of each community, and be willing to adjust project designs and locations to address local concerns, she said.

There are two contrasting approaches to community engagement: DAD (decide, announce, defend) and MUM (meet, understand, modify). DAD is a top-down approach, where companies dictate project details to the community, often failing to gain social acceptance. In contrast, MUM is a bottom-up approach that involves impacted communities in the early stages of the project, allowing them to provide meaningful input into project design.

Dr Lewis emphasised the need to earn and maintain a “social licence” for projects and that developers should explore benefit-sharing arrangements or compensation wherever possible to meet local needs.

A farmer’s perspective

Colin Bateman, the director and co-founder of Timoleague AgriGen, shared his firsthand experience of farming alongside a 600kWe AD plant located in Cork. Despite encountering ongoing regulatory challenges, the development of the plant has had overwhelmingly positive effects on both him and his farm business.

At his AD plant, various organic materials such as slurry, food processing waste, and waste from the drinks industry are used to produce approximately 250m3 of biogas per hour. This biogas is then combusted to generate electricity, which is exported to the grid. The digestate byproduct from the AD process is a valuable resource on his farm.

Colin explained that each tonne of digestate supplies 4kg of nitrogen, 0.5-0.6kg of phosphorus and 1.5kg of potash. He customises the application rates of digestate to different crops based on their specific requirements and soil indices. As such, he often finds that he can reduce or eliminate the use of chemical fertilisers, as the digestate provides the necessary nutrients. The conference concluded with a summary of the day by Salters Sterling, a respected figure within the community and a driving force behind initiatives like Birr20:20 Vision throughout his lifetime.

The author Stephen Robb is currently involved in a family/community proposal for an anaerobic digestion facility in Co Donegal.

Sean Loughnane, Birr 20:20 Vision, chairman.

Dr Deirdre Lewis, SLR Consulting.

Minister Pippa Hackett.

Edward Burgess,Teagasc.

Oisin Doherty, Technical Lead for Biogas at ORS.

Graeme Lochhead MSc commercial director, Nephin Renewable Gas.

Jackie Cahill TD.

John Feehan, MRIA, formerly Dept.of Agriculture, UCD.

Edward Burgess, Teagasc, and Salters Sterling.