E.ON Energy Infrastructure Solutions and Orcan Energy have jointly commissioned a state-of-the-art Organic Rankine Cycle (ORC) system in the historic “Glass Cathedral” by Bauhaus founder Walter Gropius—home to Kristall-Glasfabrik Amberg GmbH & Co. KG. This pioneering project optimizes energy consumption in the energy-intensive glass manufacturing process and significantly reduces the company’s CO₂ emissions.
“Reusing the energy generated during production instead of releasing it unused into the environment is a significant progression in extending the value chain. It combines modern technology with influential German architecture from the 20th century in this historic setting. The most challenging task of implementation was the planning process: the construction of the project had to be carried out within a six-week timeframe during the so-called ‘tank revision’. This renewal of the glass melting tank takes place every twelve years – timing was of particular importance,” said Christopher Link, project manager at E.ON.
The landmark industrial building, constructed in 1970 and one of Gropius’s final works, is now being transformed for a more sustainable future in glass production.
During the manufacturing process, the glass furnace is kept at a constant melting temperature of nearly 1,500°C. This generates hot exhaust gases, whose thermal energy previously went unused. The newly installed ORC system captures this waste heat using a heat exchanger, transferring it to a glycol-water mixture. This in turn heats an organic working fluid, which evaporates and drives an expansion unit connected to a generator, producing electricity. After power generation, the vapor condenses and is cycled back through the system.
Kristall-Glasfabrik Amberg produces approximately 23 million premium goblets and crystal glasses annually. With an annual energy demand of around 70 gigawatt hours, improving efficiency is critical. The innovative ORC-based waste heat recovery system now allows the facility to convert unused process heat into on-site electricity—without the need for additional fuel. This not only enhances energy efficiency but also strengthens the resilience and stability of the plant’s energy supply.
