Ireland’s largest producer of natural gas, Nephin Energy, has set out plans to develop a range of new anaerobic digestion (AD) plants across the island.

Nephin Energy holds a 43.5% interest in the Corrib Gas field, which currently supplies 25% of Ireland’s gas demand.

With gas supply at Corrib set to dwindle in the coming years, and major national targets in place for biomethane, the company is aiming to develop 20 to 30 AD plants to produce 1.2 to 1.5 terrawatt hours of biomethane. This would equate to around 25% of Ireland’s 2030 target.

Earlier this year, the company set up Nephin Renewable Gas and hired a seasoned team of Irish and UK AD experts to develop the projects.

Feedstock

Speaking to the Irish Farmers Journal at this year’s National Ploughing Championships, the company confirmed that it currently has 10 AD sites secured, predominantly in Munster, and is working with farmers on further sites.

Around 80% of the feedstock will come from agricultural sources, and each plant will require around 3,000ac of grass silage or wholecrop and around 40,000t of slurry.

Approximately 60% of the “anchor feedstock” for each plant will come from farmers who have signed up for 15-year feedstock supply contracts.

The first projects are expected to be submitted for planning by early next year

Each plant will produce around 60 GWh (gigawatt-hours) of biomethane.

The plants follow a similar layout, with six AD tanks, a feedstock building, a nutrient recovery system, and gas upgrading equipment across a 10ac site. The plants will either be connected directly to the gas grid or be located off-grid.

Dr Tony Yates, managing director of Nephin Renewable Gas, explains that the company believes AD is the right answer, in particular, to dealing with nitrates challenges, and the technology allows for the better management and use of nutrients. In addition, each plant is expected to create 70 new direct and indirect jobs.

The first projects are expected to be submitted for planning by early next year.

Nephin is a wholly owned subsidiary of the Canada Pension Plan Investment Board (CPPIB), one of the largest pension investment funds in the world. In 2023, the CPP Fund had net assets of €397bn, with €70bn invested in Europe alone.