RheinEnergie to install 1.82MW ammonia heat pump system at German glassworks
Germany – RheinEnergie is constructing a 3.5MW electric heat supply system for Ardagh Glass GmbH at its container-glass plant in Obernkirchen, Lower Saxony, north-west Germany.
The project, being delivered through RheinEnergie – next energy solutions, will combine waste heat recovery with two ammonia heat pumps, each providing 911kW of heating capacity. The installation is scheduled to enter operation in November 2026 and replace the site’s existing gas-based heat supply.
Heat recovery combined with ammonia heat pumps
The two heat pumps provide a combined 1.822MW of heating capacity and use ammonia, or R717, as the refrigerant. R717 has a global warming potential of zero under the EU F-gas Regulation.
The wider heat supply system is rated at around 3.5MW and also incorporates hot-water and waste-heat recovery, although RheinEnergie has not published a detailed capacity breakdown.
The installation will change how heat is provided across the glassworks. The site previously used steam generated from hot flue gases produced by a conventional glass furnace. The new system will instead combine electrically driven heat pumps with recovered heat as Ardagh moves towards greater electrification of the site.
Ardagh said warm process air from four glass annealing ovens will be recovered and redirected towards the plant’s packing area. The heat pump manufacturer, source and flow temperatures, COP, electrical input and expected emissions reductions for the installation have not been disclosed.
Wider decarbonisation at Obernkirchen
Ardagh has operated its NextGen hybrid glass-melting furnace at Obernkirchen since 2023. The furnace is separate from the new heat supply system but forms part of wider work to reduce fossil fuel consumption at the site.
Ardagh reported in 2024 that bottles produced using the furnace were achieving a modelled 64% reduction in carbon dioxide emissions. At the time, the furnace was averaging 60% electrical heating and using up to 70% recycled glass cullet.
Germany’s Competence Centre on Climate Change Mitigation in Energy-Intensive Industries lists the NextGen Furnace project at around €30.9m, with grant funding of approximately €12.4m. Those figures relate to the furnace project and have not been identified as funding for RheinEnergie’s new heat supply installation.
