Agriculturally produced biomethane can be delivered sustainably and at scale to help reduce on-farm emissions and decarbonise Ireland’s energy system.

This can be done without reducing the national herd, disrupting food production, intensifying agricultural activities or impacting on biodiversity, according to a new Sustainability of Biomethane Production in Ireland report issued today (Thursday, October 21).

Undertaken by Devenish Nutrition and KPMG Sustainable Futures, the report draws on existing academic research, as well as data and on-farm experience from the Dowth Research Farm in Co. Meath.

It produces internationally recognised farm research focused on the scientific understanding of sustainable agriculture production and practices, using real-world data.

Biomethane in Ireland

The report concludes that an Irish agriculture-led biomethane industry, developed according to international best practice, is aligned with current and emerging policy direction and can meet the EU Renewable Energy Directive II (RED II) requirements.

It found that the process for producing biomethane could reduce the direct application of raw slurry to land.

The resulting digestate by-product could displace chemical fertilisers and pesticides, decreasing ammonia and nitrous oxide emissions, and improving soil quality and soil carbon sequestration.

Devenish Nutrition’s sustainable agricultural manager, David Hagan, said:

“The challenge of addressing on-farm emissions has emerged as one of the most difficult pieces of the climate policy jigsaw.

“Ensuring a sustainable livelihood for primary producers and supporting growth in our food industries, while also protecting our environment, is both critical and challenging.

“This report outlines how Ireland can deliver a sustainable, agriculture-led biomethane industry,” he added.

EU Green Deal

The EU Green Deal highlighted biomethane as a vital tool in decarbonising European agriculture and energy systems.

The European Commission identified Ireland as having the highest potential per capita to produce the carbon neutral renewable gas.

Ireland began its journey to a net-zero carbon gas network in 2019, with the introduction of domestically produced biomethane in Co. Kildare.

This was through Ireland’s first purpose built injection facility in Cush and Gas Networks Ireland (GNI) was recently granted planning permission for a second renewable gas injection point near Mitchelstown in Co. Cork that has the potential to heat up to 64,000 homes.

GNI head of commercial and corporate affairs, Ian O’Flynn, said:

“Gas Networks Ireland’s vision is to replace natural gas with renewable gases, such as biomethane and hydrogen, to substantially reduce the country’s carbon emissions while complementing intermittent renewable electricity and ensuring a secure energy supply.

“Agriculturally produced biomethane can be delivered sustainably and at scale to help reduce on-farm emissions and support more sustainable food supply chains, seamlessly replace natural gas in the national gas network, decarbonise the energy system, diversify our indigenous energy supply, enhance our energy security and generate significant employment opportunities in rural Ireland, creating additional income sources for farmers and local communities.”

Ian O’Flynn, Gas Networks Ireland with David Hagan, Devenish. Image: Orla Murray /Coalesce

Further findings of the biomethane report

The report identifies a number key activities to deliver significant emissions savings (including carbon dioxide and nitrous oxide), that align with EU and national policy targets.

These include meeting grass demand for a biomethane industry solely through sustainable, incremental fodder growth, and sowing a multi-species swards system to decrease emissions while enhancing biodiversity.

Achieving the current national target of 1.6TWh of biomethane by 2030 would result in carbon dioxide (CO2) savings of approximately 320,000t.

These CO2 emission savings could rise to approximately 1.9 million tonnes per annum based on the potential, identified in the report, of improved efficiency across land already in agricultural production.

Digestate produced during biomethane production could reduce nitrous oxide emissions by 37% (more if multi-species swards are used), when used as an organic fertiliser.

This would avoid emissions associated with chemical fertiliser and replace untreated slurry to displace significant greenhouse gas (GHG) emissions.

Beef and dairy farms

Replacing all nitrogen use with digestate on beef farms could reduce on-farm emissions by 25%, or 3.9t of CO2 equivalent (CO2e) per farm.

If 10% of farmers committed to this, there would be an estimated combined saving of 30,380t of CO2e.

Replacing all nitrogen use with digestate and growing multi-species swards on dairy farms could reduce on-farm emissions by 66%, or 9.3t of CO2e per farm.

If 10% of farmers committed to this, there would be an estimated combined saving of 14,897t of CO2e.