RheEnergise, the innovative UK energy storage company, has celebrated a significant achievement with its first High-Density Hydro® (HD Hydro) project in Devon now operating at full power, consistently delivering the output it was designed to achieve. This milestone marks a new chapter in the development of long-duration energy storage (LDES) and paves the way for commercial-scale deployments in the UK and internationally.
High-Density Hydro is a next-generation evolution of traditional pumped storage hydropower that uses a specially formulated, environmentally benign fluid that is around 2.5 times denser than water. By replacing water with this high-density fluid in a closed-loop system, HD Hydro can deliver substantially more energy from the same elevation difference, enabling projects to be built on smaller hills rather than in remote mountainous regions. The higher fluid density increases energy and power output, expands the number of potential sites, and reduces construction costs and timelines compared to conventional pumped hydro projects.
Located on the outskirts of Plymouth, the Cornwood project is the first of its kind anywhere in the world. With a peak generation capacity of 500 kW, it is equivalent to powering around 400 homes for a year when run continuously, and it already supports the energy needs of Sibelco’s Cornwood mine during periods of high demand.
Stephen Crosher, Chief Executive of RheEnergise, said the team is delighted that the system is performing exactly as predicted and that reaching full power is a major milestone in their growth ambitions. The successful operation of this demonstrator has de-risked the technology and will underpin efforts to scale HD Hydro into commercial projects across the UK, continental Europe and North America within the next few years.
Government backing through the UK Department of Energy Security & Net Zero’s innovation programme has been instrumental in bringing the project to fruition. With global interest growing in scalable, low-carbon energy storage solutions, this achievement highlights RheEnergise’s potential to play a key role in the transition to a cleaner energy future.
