German manufacturer Weltec Biopower is currently building a biomethane plant for the Irish company Evergreen Agricultural Enterprises Limited. The plant at the company’s headquarters in Monasterevin, County Kildare, will go into operation in mid-2026 after a total construction period of 11 months. The location offers the operator logistical advantages, among other things: “On the one hand, it is well connected to the M7 motorway. In addition, the national gas network for direct biomethane feed-in is in the immediate vicinity,” emphasises Patrick Meade, managing director of Evergreen.
The €50 million project comprises four digesters and one stainless-steel secondary digester, each with a volume of 4,900 cubic metres. These are mainly used to ferment production residues and by-products from the Irish beer and whiskey industry. The materials are readily available and do not compete with feed production, as they are unsuitable for animal feed. Three additional tanks are used to store liquid substrates. “Despite its size, the plant, with an annual processing capacity of 165,000 tonnes, will be built in just six months of pure construction time. Construction is proceeding according to plan and mechanical completion is scheduled for the end of this year,” said Tobias Gerweler, managing director of Weltec Biopower. “The decision not to use grass silage was a conscious one, so that we would not be competing with the livestock industry,” Patrick Meade continues. A combined heat and power plant (CHP) installed on site generates around one megawatt of power for the operation of the plant and supplies heat for the digesters.
Three rotating long-axis agitators and three submersible motor agitators in the tanks support the effective digestion of the substrate mix. The biogas is collected in the digesters with double-membrane roofs and processed into biomethane using membrane technology. It then enters the public gas grid 20 metres away via the feed-in point. Once commissioned, the plant will produce around 1,300 standard cubic metres of biomethane per hour – equivalent to around 110 GWh of energy per year. The annual output of 65,000 tonnes of digestate is stored in a covered concrete lagoon and delivered to farmers separately as liquid and solid fractions.
Published December 2025