Covestro and partners launch a large-scale heat battery in Brunsb眉ttel, enabling renewable-powered industrial steam and cutting thousands of tonnes of CO2 annually.
Covestro, together with technology partner Rondo Energy, has marked a major milestone in industrial decarbonization with the groundbreaking of an innovative heat battery at its Brunsb眉ttel production site. The project brings together political leaders, industry stakeholders, and clean-energy innovators to showcase how large-scale manufacturing can transition away from fossil fuels while maintaining operational reliability.
At the heart of the initiative is the Rondo Heat Battery, a system designed to absorb surplus electricity from renewable sources when power is abundant and prices are low. This electrical energy is converted into thermal energy and stored in specially engineered bricks. When required, the stored heat is released to generate high-temperature steam that can be used continuously in industrial production processes. This approach directly addresses one of the core challenges of the energy transition: renewable electricity is intermittent, while industrial demand for heat and steam is constant.
The project has particular significance for the German state of Schleswig-Holstein, which has positioned itself as a leader in renewable energy deployment. Tobias Goldschmidt, the state鈥檚 Minister for Energy Transition, Climate Protection, Environment and Nature, highlighted the broader implications during the ceremony. He emphasized that the rapid expansion of renewable power is strengthening Schleswig-Holstein as a business location and enabling forward-looking projects such as this heat battery. According to Goldschmidt, initiatives like the Brunsb眉ttel installation enhance energy sovereignty, support economic competitiveness, and play a crucial role in achieving climate-neutrality targets.
The 100-megawatt-hour Rondo Heat Battery is scheduled to become operational by the end of 2026. Once online, it is expected to supply around ten percent of the total steam demand at the site. This will translate into a reduction of up to 13,000 tonnes of carbon dioxide emissions annually, making a meaningful contribution to the company鈥檚 decarbonization roadmap. Financial and strategic backing for the project comes from Breakthrough Energy Catalyst and the European Investment Bank, underscoring the project鈥檚 importance at both European and global levels.
From a technological standpoint, the heat battery represents a blend of proven materials and modern automation. The concept of storing heat in bricks has been used in steel production for centuries, but the integration with advanced control systems and renewable electricity allows for a new level of efficiency and flexibility. The stored heat feeds a conventional boiler, producing steam without direct emissions. When powered by renewable electricity, this enables continuous, emission-free steam generation independent of fluctuations in the power grid.
Eric Trusiewicz, CEO of Rondo Energy, noted that the project addresses two of Europe鈥檚 most pressing challenges simultaneously. As renewable generation grows, periods of excess low-cost electricity are becoming more common. At the same time, industrial players require dependable and affordable energy to remain competitive. According to Trusiewicz, the Brunsb眉ttel heat battery demonstrates that clean industrial heat can be reliable, cost-effective, and a powerful tool for balancing electricity grids while reinforcing Europe鈥檚 industrial resilience and energy security.
Steam production remains a core component of operations at the Brunsb眉ttel site and accounts for a substantial share of energy consumption. Currently, this steam is largely generated using natural gas. Based on the performance and operational experience gained from this installation, Covestro plans to assess whether similar heat battery systems could be deployed on a broader scale across other sites, potentially accelerating the transition toward climate-neutral industrial production.
