UK Engineers Make Hydropower Work on Ordinary Hills

Engineers in Devon, England just cracked a problem that's stumped the energy industry for decades: how to store clean power without building giant dams in the mountains.

The solution? Replace water with a mineral-rich liquid that packs 2.5 times more energy punch per liter. Company RheEnergise spent years developing the dense fluid, which behaves like water but stores far more power.

The technology works like traditional hydropower but on a much smaller scale. The heavy liquid sits in a hilltop reservoir, flows downhill through underground pipes to spin turbines, then gets pumped back up when electricity is cheap. Because it's so dense, the system needs less liquid and less dramatic terrain.

The pilot project sits on just an 80-meter hill made from old quarry rock. No pristine valleys flooded, no communities displaced, no ecosystems drowned under massive reservoirs.

Integration engineer Peter Hawkins says getting machinery to handle the ultra-dense fluid presented serious challenges. "We've had issues with pumping, transferring, mixing it effectively and quickly," he explained. But the team persisted until the fluid performed reliably.

The Ripple Effect

This breakthrough addresses renewable energy's Achilles heel: storage. Solar panels go dark at night. Wind turbines sit idle on calm days. But this system stores excess power from sunny or windy periods and releases it exactly when needed.

CEO Stephen Crosher believes the world needs 50 times more storage capacity than exists today. "We are part of the answer to the energy transition to decarbonize the world, store the electricity, create stability and create lower prices for consumers," he said.

The potential reaches far beyond the UK. Visitors from around the globe are touring the Devon site, exploring whether the technology could work in their regions. Places previously ruled out for hydropower because of flat terrain could suddenly become viable.

Joe Butchers, who lectures on engineering at the University of the West of England, notes that hydropower must innovate to compete with falling solar and battery costs. This dense-liquid approach does exactly that.

RheEnergise plans to build its first full-scale plant within a few years, generating 20 times more power than the current test site. The company sees its technology working alongside wind and solar, not replacing them, filling the critical gap between generation and consumption.

Clean energy that works anywhere, stores reliably, and leaves landscapes intact sounds too good to be true, but it's already spinning turbines on a small English hill.