During the past 30 years, over 17,500 anaerobic digestion (AD) plants developed across Europe, over 9,000 of which are located in Germany. In Northern Ireland, there are around 60 plants in operation. AD has created a new enterprise for many farmers and an additional market for crops and slurries.
AD is the natural process of the decomposition of organic matter in the complete absence of oxygen. The AD process begins when organic feedstock such as grass, crops, slurries, food, etc are put inside a sealed tank (anaerobic digester) and heated.
Anaerobic microorganisms break this feedstock down into simpler organic matter and, in the process, release biogas.
This biogas consists of around 50% to 60% methane and can be used to make electricity or upgraded and injected into our gas network or compressed to make transport fuel.
The material remaining after the AD process is called digestate and is a valuable source of fertiliser.
Renewable biogas has been proven to be the most economical way of decarbonising Ireland’s heat sector.
There are only a handful of working farm-based AD plants in Ireland. But after years of false dawns, momentum is finally gathering for the development of a larger-scale biogas industry in the country.
Roadmap
The structure of Ireland’s biogas sector is likely to be unique when compared to any other European country. Traditionally, biogas produced from AD was combusted in a combined heat and power plant (CHP) located on site. This generates electricity at around 35% efficiency, which would be exported to the electricity grid, and heat at around 50% efficiency which could be used for heating purposes.
However, Ireland’s biogas model will see biogas upgraded to biomethane and injected into the national gas grid. While this process is more expensive than CHP, the end use, ie generating heat, is much more efficient. There are over 400 AD plants across Europe producing biomethane and this is set to increase.
Gas Networks Ireland (GNI) is a semi-state company with responsibility for the delivery of gas to the country and has committed to fully decarbonising its gas network by 2050. Its initial phase of the plan is to have 20% renewable gas on the network by 2030.
Farm-based AD will play an integral part in meeting this target. Biogas will be purified to natural gas standard at the AD site. GNI will collect the gas and bring it to a central grid injection (CGI) facility located on the gas transmission network for grid injection. Alternatively, the gas pipeline can be extended directly to an AD facility if economically feasible.
Unlike other European countries, biomethane can be injected directly into the gas grid in Ireland without the need for propane enrichment. Earlier this year, we saw the first farm-produced biomethane collected by GNI and injected into the national gas grid.
Green Generation anaerobic digester facility in Nurney, Co Kildare.
Costs
At current levels of carbon tax, the production of biomethane is more expensive than its fossil fuel equivalent and will require financial support.
The capital cost of building an AD plant is also significant.
For example, the minimum cost of a 20GWh/yr plant (equivalent to 1,000kW in size) including biomethane upgrading technology is expected to be in the region of €5.5m.
Government support will be essential to make this a reality. In July, the Irish Bioenergy Association (IrBEA) and the Composting and Anaerobic Digestion Association of Ireland (Cré) outlined the potential for an initial network of 25 strategically located AD plants around the country. It states that this phase would require €40m in Government support.
The Renewable Gas Forum Ireland (RGFI) published details of a KPMG-commissioned report earlier this year into a business case for biomethane production in Ireland.
In order to achieve RGFI’s vision of replacing 12% of current natural gas consumption with low-carbon renewable gas, approximately 227 agri- and industry-led AD plants, along with 15 larger waste AD plants, will need to be developed by 2030. This will require a capital investment in the region of €1.5bn, along with a Government subsidy.
Funding
Pivotal to the development of biogas across Europe has been a robust support scheme for AD projects offering 15- to 20-year contracts.
RGFI and KPMG have analysed that a total income of around €8.8 c/kWh is required to make a farm-scale 20GWh/yr plant viable. At current energy prices, this would mean a subsidy of between 5c/kWh and 6c/kWh.
Crucially, the cost-benefit analysis into a subsidy for biomethane found that for every €1 of support provided, €1.26 would be returned due to wider benefits to the economy.
While Minister for Communications, Climate Action and Environment Richard Bruton may have stopped short of pledging support for Ireland’s biogas industry, there is a growing sense that some support mechanism may be possible. This will become clearer when the final version of the National Energy and Climate Plan (NECP) is published.
The Irish Farmers Journal recently spoke to Ian Kilgallon, innovation manager with GNI about the future of biomethane in Ireland.
Read more
Listen: will the tillage industry miss out on Ireland’s biogas boom?
Listen: a business case for biomethane production in Ireland
During the past 30 years, over 17,500 anaerobic digestion (AD) plants developed across Europe, over 9,000 of which are located in Germany. In Northern Ireland, there are around 60 plants in operation. AD has created a new enterprise for many farmers and an additional market for crops and slurries.
AD is the natural process of the decomposition of organic matter in the complete absence of oxygen. The AD process begins when organic feedstock such as grass, crops, slurries, food, etc are put inside a sealed tank (anaerobic digester) and heated.
Anaerobic microorganisms break this feedstock down into simpler organic matter and, in the process, release biogas.
This biogas consists of around 50% to 60% methane and can be used to make electricity or upgraded and injected into our gas network or compressed to make transport fuel.
The material remaining after the AD process is called digestate and is a valuable source of fertiliser.
Renewable biogas has been proven to be the most economical way of decarbonising Ireland’s heat sector.
There are only a handful of working farm-based AD plants in Ireland. But after years of false dawns, momentum is finally gathering for the development of a larger-scale biogas industry in the country.
Roadmap
The structure of Ireland’s biogas sector is likely to be unique when compared to any other European country. Traditionally, biogas produced from AD was combusted in a combined heat and power plant (CHP) located on site. This generates electricity at around 35% efficiency, which would be exported to the electricity grid, and heat at around 50% efficiency which could be used for heating purposes.
However, Ireland’s biogas model will see biogas upgraded to biomethane and injected into the national gas grid. While this process is more expensive than CHP, the end use, ie generating heat, is much more efficient. There are over 400 AD plants across Europe producing biomethane and this is set to increase.
Gas Networks Ireland (GNI) is a semi-state company with responsibility for the delivery of gas to the country and has committed to fully decarbonising its gas network by 2050. Its initial phase of the plan is to have 20% renewable gas on the network by 2030.
Farm-based AD will play an integral part in meeting this target. Biogas will be purified to natural gas standard at the AD site. GNI will collect the gas and bring it to a central grid injection (CGI) facility located on the gas transmission network for grid injection. Alternatively, the gas pipeline can be extended directly to an AD facility if economically feasible.
Unlike other European countries, biomethane can be injected directly into the gas grid in Ireland without the need for propane enrichment. Earlier this year, we saw the first farm-produced biomethane collected by GNI and injected into the national gas grid.
Green Generation anaerobic digester facility in Nurney, Co Kildare.
Costs
At current levels of carbon tax, the production of biomethane is more expensive than its fossil fuel equivalent and will require financial support.
The capital cost of building an AD plant is also significant.
For example, the minimum cost of a 20GWh/yr plant (equivalent to 1,000kW in size) including biomethane upgrading technology is expected to be in the region of €5.5m.
Government support will be essential to make this a reality. In July, the Irish Bioenergy Association (IrBEA) and the Composting and Anaerobic Digestion Association of Ireland (Cré) outlined the potential for an initial network of 25 strategically located AD plants around the country. It states that this phase would require €40m in Government support.
The Renewable Gas Forum Ireland (RGFI) published details of a KPMG-commissioned report earlier this year into a business case for biomethane production in Ireland.
In order to achieve RGFI’s vision of replacing 12% of current natural gas consumption with low-carbon renewable gas, approximately 227 agri- and industry-led AD plants, along with 15 larger waste AD plants, will need to be developed by 2030. This will require a capital investment in the region of €1.5bn, along with a Government subsidy.
Funding
Pivotal to the development of biogas across Europe has been a robust support scheme for AD projects offering 15- to 20-year contracts.
RGFI and KPMG have analysed that a total income of around €8.8 c/kWh is required to make a farm-scale 20GWh/yr plant viable. At current energy prices, this would mean a subsidy of between 5c/kWh and 6c/kWh.
Crucially, the cost-benefit analysis into a subsidy for biomethane found that for every €1 of support provided, €1.26 would be returned due to wider benefits to the economy.
While Minister for Communications, Climate Action and Environment Richard Bruton may have stopped short of pledging support for Ireland’s biogas industry, there is a growing sense that some support mechanism may be possible. This will become clearer when the final version of the National Energy and Climate Plan (NECP) is published.
The Irish Farmers Journal recently spoke to Ian Kilgallon, innovation manager with GNI about the future of biomethane in Ireland.
Read more
Listen: will the tillage industry miss out on Ireland’s biogas boom?
Listen: a business case for biomethane production in Ireland
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