Covestro AG (Leverkusen, Germany) is partnering with Rondo Energy, Inc. (Oakland, Calif.) to install an innovative heat battery for the first time: The Rondo Heat Battery stores intermittent renewable electricity and delivers continuous high-temperature steam, thus offers a sustainable alternative to steam generation with fossil fuels.
The Breakthrough Energy Catalyst foundation set up by Bill Gates and the European Investment Bank (EIB) are supporting this installation of the Rondo RHB100 heat battery, which is scheduled to begin operation at Covestro’s Brunsbüttel, Germany site at the end of 2026. The project will then produce ten percent of the steam required at the site, saving up to 13,000 tons of CO2 emissions per year.
The Covestro site in Brunsbüttel. © Covestro
Rondo Heat Batteries combine established materials and cutting-edge automation to capture electricity and deliver high-temperature heat and power. Electrical energy is stored as heat, using bricks that have been used for heat storage at steel mills for centuries. The heat powers an ordinary boiler to deliver zero-emission steam. Renewable electricity can be intermittently stored when there is an excess available and a constant amount of steam can still be generated continuously.
“As an innovation company, we are always excited when we can further develop and test promising ideas that can bring us closer to our goals of a circular economy and climate-neutral production,” says Dr. Thorsten Dreier, CTO of Covestro. “The heat battery is such an idea: a new technology that allows us to go one step further on our way to a sustainable future.”
“Rondo Heat Batteries deliver deep decarbonization by changing the fuel, not the factory,” said Eric Trusiewicz, CEO of Rondo Energy. “We’re honored to be working with Covestro to prove our safety, reliability, and efficiency under real conditions on a large scale over a long period of time. And we’re excited to be deploying in Brunsbüttel, where large flexible electricity loads are particularly valuable to the electricity grid.”
For Covestro, steam generation is an important part of the production process and accounts for a large proportion of energy consumption. The learnings from this first heat battery installation will provide experience and insights for Covestro to be able to assess whether larger-scale deployments are possible.