RheEnergise Secures €2.5 Million EIC Grant to Scale High-Density Hydro® Energy Storage Technology
RheEnergise, a UK clean-energy startup developing its High-Density Hydro® long-duration energy storage technology, recently secured a €2.5 million (≈ £2.15 million) grant from the European Innovation Council (EIC) Accelerator to advance its R&D work. This grant represents a significant non-dilutive funding boost for the company as it scales its technology toward commercial deployment.
RheEnergise’s technology revolves around a novel form of pumped hydro storage using a dense fluid that is 2.5 times heavier than water, allowing storage systems to operate on gentler slopes and lower elevations than traditional pumped hydro. This design flexibility opens more deployment sites than conventional approaches require. The EIC grant is intended to support RheEnergise’s work on scaling up its prototype systems, strengthening its intellectual property, and moving toward its first grid-connected commercial systems.
The company already has strong backing from government sources. Previously, RheEnergise was awarded £9.5 million in UK government funding to support its development roadmap, including a 500 kW demonstrator project. The EIC funding is expected to complement that earlier support, enabling the startup to continue pushing its development agenda.
RheEnergise’s demonstrator site is located in Cornwood, near Plymouth in Devon, where the company has recently completed the main mechanical works. Key components such as turbines, pumps, and generators have been installed, signaling progress in transitioning from civil construction to operational phases. RheEnergise describes the site as a “real-life test laboratory” for its High-Density Hydro® system, and plans to enter fluid testing soon. The company expects to commission its first grid-scale long-duration hydro system within the next two to three years.
In parallel with the grant award, RheEnergise is running fundraising campaigns in North America through platforms such as Republic, aiming to raise capital to accelerate expansion into the U.S. and Canada. The company is offering investors the opportunity to participate in its next round, with a funding target in the range of $1.5 million to $3.0 million. So far, non-dilutive funds (grants) have formed a significant portion of RheEnergise’s capital mix, with reports indicating that over £11 million has been raised via grants and roughly £5 million via equity to date. The company also benefits from R&D tax credits and rebates to support its operating needs.
RheEnergise’s fundraising is designed to support multiple strategic goals: accelerating development of its High-Density Hydro® systems, expanding its IP portfolio, building a robust pipeline of commercial projects globally, and scaling its internal team and infrastructure. The company also plans to deepen its commercialization efforts, converting technical milestones into deployed systems and customer contracts.
Beyond the UK, RheEnergise has identified international markets for its technology, with agreements or active discussions underway in South America, Australia, and mainland Europe. Its North American fundraising campaign underscores the company’s intention to bring its energy storage solutions to that region as well.
The combination of strong public funding, technical progress at its demonstrator site, and a growing global outreach strategy positions RheEnergise to become a noteworthy player in the long-duration energy storage (LDES) sector. Its High-Density Hydro concept offers potential advantages of site flexibility and cost competitiveness versus battery storage and conventional pumped hydro. As the energy transition continues to demand scalable, dispatchable power storage, RheEnergise’s advances may help bridge gaps in grid flexibility and renewable integration.
