The movers and shakers of the Northern Irish anaerobic digestion (AD) industry once again descended on the ICC in Belfast for the Anaerobic Digestion and Bioresources Association (ADBA) 2025 biogas conference. Similar to the Republic, and indeed the rest of the UK and Europe, the focus of AD has shifted from electricity generation to biomethane gas production.

Earlier this year, the Northern Ireland Department for the Economy committed to progressing a support mechanism for biomethane as part of its energy strategy.

Delegates at the conference once again heard that Northern Ireland’s manures and slurries alone could supply feedstock for up to 80% of the region’s gas needs, while enabling better nutrient management.

While the potential is clearly there, the main question on everyone’s mind was what has changed since last year – is there work underway on a new policy or scheme to kick-start the second generation of AD in Northern Ireland and provide a pathway for existing electricity plants to transition to biomethane?

To be frank, the answer is no. While Minister of Agriculture, Environment and Rural Affairs, Andrew Muir, who spoke at the conference, was highly supportive of biomethane and expressed his ambition to see the sector develop here, he had little in the way of concrete plans that might attract investment.

Overlooked

According to ADBA figure’s there are 84 operational AD plants in Northern Ireland, with just one of them producing biomethane, and one producing liquified biomethane. There is a one other large scale biomethane plant in development which is likely to double national production.

Northern Ireland has a target to reduce greenhouse gas emissions by 48% by 2030. According to the Climate Change Committee, if anaerobic digestion is developed strategically, it could reduce emissions by around 0.3 million tonnes of CO2e by 2035. However, in his opening address, Chris Huhne, ADBA chair, explained that biomethane continues to be overlooked in UK policy, commenting on recent modelling data.

“We found that in the UK, we could save £298bn, about 7% of the entire cost of reaching net zero, when biomethane is properly modelled. Up until that point, no one had modelled biomethane,” he told attendees.

“When you inject a dispatchable resource like biomethane, it means other renewables don’t have to work as hard. Offshore wind, hydrogen, all of these savings come about by using biomethane.”

However, he warned that Northern Ireland is falling behind, alluding to progress south of the border.

“The Republic announcements are the latest in a series of flags showing that you need to catch up,” he said.

Schemes

Dr Gareth Mottram, policy lead for the ADBA, told attendees that over the next five to 10 years, Northern Ireland’s existing AD plants will begin to exit the NI Renewables Obligation Certificates (ROCs) scheme. There is currently around 52 MW equivalent being produced from biogas combined heat and power plants, and we could lose half of that by 2035 unless a scheme is introduced to support conversions, he said.

While there is an opportunity to convert these AD plants to biomethane and capture the benefits of this gas, there may also be scope for the gas to be transported across the border to the Republic, where a new obligation scheme will create significant demand.

At present, there is no meaningful movement towards a biomethane scheme in Northern Ireland, and policymakers appear to be unsure of how to proceed. However, Mottram noted that there is potential for Northern Ireland to join a UK-wide programme. This would mean that the levy used to fund the premium price for biomethane could be shared across all UK gas users, rather than being borne solely by Northern Ireland consumers. This approach was critical to the success of the ROCs scheme in Northern Ireland.

Hand in hand

“Particularly in relation to ammonia, we are considering representations on how to find a way forward, to meet our obligations to reduce ammonia emissions, while also finding ways to enable technology.”

These were the words of Minister of Muir, who was enthusiastic about the prospects of developing a biomethane sector alongside tackling Northern Ireland’s nutrient and emissions challenges.

Speaking to attendees, he said that, from the outset, projects must demonstrate robust digestate management and ammonia reduction plans, outlining clear pathways to remove and export excess phosphorus.

He added that investors need clarity on routes to market and network connections. He said he will take views from the industry and international examples to make Northern Ireland’s proposition investable within the local policy framework.

How to square the circle of meeting the rules around ammonia and the uncertainty of the Nutrient Action Programme (NAP), while trying to get an AD plant through planning, was highlighted as a key challenge.

However, he said that in relation to ammonia in particular, it largely comes down to the interpretation of the legislation, and he believes a way forward can be found on that.

In terms of a support scheme, he explained that this responsibility sits with another department, ie the Department for the Economy. He said there is clear feedback that support is needed in this area and added that getting the NAP in place first is essential, as that will also provide clarity on this issue, since both are closely linked. In many ways, he said, this is a defining point, and his goal is to have clarity by next spring.

Key takeaways

There was no doubt that there was real enthusiasm in the room, with developers, farmers, industry representatives and some policymakers in attendance. However, it is clear that biomethane development has not been at the forefront of Northern Ireland’s energy policy and changing that will require concerted effort.

As the story of the RHI looks set to conclude, there are suggestions that some of that funding could be redirected to support new AD plants, according to Jonathan McLenaghan, deputy president of the UFU.

A key message from Jack Blakiston Houston of BH Estates was that AD feedstocks should be limited to slurry, manures and wastes, and not crops.

Meanwhile, Northern Ireland’s efforts to separate slurry at source may be improved through newer techniques such as chemical flocculation, according to AFBI Gary Lyons.

All attendees in the room agreed that without swift and well-thought out policy and support, the biomethane industry will struggle to take off.