Covestro, Rondo Kick Off EIB-Backed 100 MWh Heat Battery to Cut Gas-Fired Steam

Covestro, a polymer materials and component manufacturer, and Rondo Energy break ground for a 100 MWh Rondo Heat Battery (RHB), which is scheduled to go into operation by the end of 2026. Covestro said in a press release that the battery project is supported by the Energy Catalyst, and the European Investment Bank (EIB) will produce 10% of the required steam at the site.

For Covestro, steam generation is an essential part of the production process and accounts for a large portion of energy consumption. The steam at the Brunsbüttel site is currently still generated with natural gas. Based on the experience with using the Rondo Heat Battery in Brunsbüttel, Covestro is evaluating whether deployment on a larger scale is possible.

Covestro explained that Rondo Heat Battery charges when there is a surplus of low-price renewable energy in the grid, stores that energy in bricks, and delivers continuous high-temperature steam for on-site production processes. Thereby, it offers a sustainable alternative to steam generation using fossil fuels, which are used in continuously running industrial processes, as the available amount of renewable energy at affordable prices fluctuates. 

The Rondo Heat Battery combines centuries-old materials with modern automation: electrical energy is stored in the form of heat, with the help of bricks that have been used as heat storage in steel mills for centuries. The heat drives an ordinary boiler that delivers emission-free steam. With electricity from renewable energy sources, a constant amount of steam can thus be continuously generated.

About The Project

For Schleswig-Holstein, the project represents an important step on the path to the climate-neutral transformation of the state.

Tobias Goldschmidt, Minister for Energy Transition, Climate Protection, Environment and Nature of the state, emphasized, "The rapid expansion of renewable energies is a booster for our business location Schleswig-Holstein and makes future-oriented projects like the heat battery possible in the first place."

Thorsten Dreier, CTO of Covestro, said,  "The heat battery is such an idea: a new technology that enables us to take another step forward on our path to a sustainable future."

“This project shows how two of Europe’s central challenges can be solved together,” said Eric Trusiewicz, CEO of Rondo Energy.  He added, “As renewable power expands, it increasingly creates daily periods of abundant, low-cost electricity. At the same time, European industry needs reliable, affordable energy to remain competitive. Together with Covestro, we are demonstrating that clean industrial heat can be both highly reliable and a powerful tool for balancing the grid — while building the energy infrastructure needed to strengthen Europe’s industrial base and energy security.”