GRAZE Gas Project and Mitchelstown Central Grid Injection Facility

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GRAZE Gas Project

The GRAZE (Green Renewable Agricultural Zero Emissions) Gas Project is led by Gas Networks Ireland  and is supported by more than €8.4m in funding from the Department of Environment, Climate and Communications’ (DECC) Climate Action Fund, as part of the Government’s national energy security framework.

Key elements of the GRAZE Gas Project include:

  1. Development of a central grid injection (CGI) facility near Mitchelstown in Co. Cork
  2. Transportation of renewable gas from anaerobic digestors to the CGI facility
  3. Two compressed natural gas (CNG) refuelling stations
  4. Vehicle funding for 74 compressed natural gas (CNG) trucks
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Mitchelstown CGI

The Mitchelstown CGI will facilitate the injection of biomethane into Ireland’s transmission network. Biomethane is a carbon neutral renewable gas produced from farm and food waste through a process known as anaerobic digestion and has already begun to seamlessly replace natural gas in the national network.

It is fully compatible with the existing national gas network, appliances, technologies and vehicles, and will ultimately replace natural gas to reduce emissions in heating, industry, transport and power generation, while also supporting the decarbonisation of the agri-food sector.

Progress to date

  • Planning permission for Ireland’s second central grid injection facility was granted by An Bord Pleanála and Cork County Council in December 2020.
  • Phase one of construction (25% build) is expected to commence in 2023.
  • This CGI in Mitchelstown facility will build on the successful development of the country’s first renewable gas injection point in Cush, Co Kildare. Biomethane first began to seamlessly replace natural gas in Ireland in small volumes in 2019. When operating at full capacity, this injection point will be able to meet the gas requirements of a 11,000 Irish homes.

Benefits of the GRAZE project

An indigenous renewable gas industry in Ireland would support numerous Irish and European climate policy targets and initiatives. In addition to addressing Ireland’s security of supply, the GRAZE project and others like it will also provide significant opportunities and benefits for rural communities and difficult to decarbonise sectors of the Irish economy.

  1. When operating at full capacity, the Mitchelstown CGI will have the potential to inject up to 700 GWh of renewable gas into the gas network. This is equivalent to fulfilling the gas requirements of up to 64,000 homes
  2. Once fully operational, the CGI facility will also result in a saving fo 130,000 tonnes of CO2 emissions per annum. Anaerobic digestion is also a key technology that can support the reduction of methane emissions arising from natural decomposition of wastes and residues, as noted in the recent EU Methane Strategy*
  3. The new facility will have the capacity to receive renewable gas produced from farm and food waste from approximately 20 local producers.
  4. In addition to reducing on-farm emissions and supporting more sustainable supply chains, the establishment of a sustainable renewable gas industry in the region would also provide significant opportunities for the local community from the sale of biomethane, feedstock used to produce the renewable gas, and a bio-fertiliser that is a by-product of the process, and facilitate sustainable circular economies, with businesses powering their operations via renewable gas made from their own waste.
  5. Digestate outputted from the AD process can be used as a replacement to conventional fertilisers on farms. Correct application of digestate derived bio-fertiliser does not have the level of run-off and emissions associated with raw animal slurry use and is one of the enablers for enhancing carbon stocks in soils


Anaerobic digestion is the breakdown of organic material (feedstock) by micro-organisms in large oxygen-free tanks (anaerobic digesters) into biogas and digestate.  This process also occurs naturally in nature as organic wastes and residues decompose releasing methane into the atmosphere. 

The anaerobic digestion process allows for the capture of biogas, which can be used to generate onsite electricity. Alternatively, it can be upgraded to biomethane and injected into the gas network.

Biomethane is a carbon-neutral renewable gas. Biogas is initially produced from farm and food waste through a process known as anaerobic digestion where the greenhouse gases created by agricultural and food waste emissions are captured and converted into energy. To be injected into the gas network, this biogas can must be upgraded to biomethane and meet the quality standards as required by Gas Networks Ireland.

The material that is used in anaerobic digestion is called feedstock. This can include animal slurries and crop residues. What goes into a digester determines what comes out, so careful choice of feedstocks is essential.  Securing a reliable feedstock supply is fundamental to profitable anaerobic digestion.

Digestate is the material remaining after the anaerobic digestion of feedstock.  Digestate can be applied as a bio-fertiliser to grass and tillage lands as a sustainable alternative to chemical fertiliser application,  offsetting carbon emissions from conventional fertilisers.

Government support

To support delivery of the GRAZE project, Gas Networks Ireland have received over €8.4 million in funding under the Climate Action Fund, which is administered by the Department of the Environment, Climate and Communications.

The purpose of the project will be to show how Ireland can diversify its gas supplies, by speeding up the roll-out of renewable gases like biomethane. Projects such as this will reduce our reliance on imported fossil fuels. The Government’s National Energy Security Framework, which sets out how Ireland is prepared to deal with potential shocks to our energy system, has highlighted the need for alternatives to natural gas, such as biomethane and hydrogen, to be developed to enhance Ireland’s security of supply and provide additional diversification for Ireland’s energy mix.

This new facility in Mitchelstown and our existing facility in Cush, County Kildare will contribute to our broader climate goals – of cutting greenhouse gas emissions by 51% by 2030 and reaching net zero emissions by 2050.


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