Hi-tech fluid makes pumped hydro more affordable

A company is deploying a first-of-its-kind demonstrator of an advanced long-duration, hydroelectricity storage system

Spotted: Clean energy sources, like solar and wind, are much better for the environment than fossil fuels, but they are less reliable. Increasingly, companies are exploring pumped hydropower as a means of storing renewable energy. But today’s conventional low-density hydro-power systems don’t use renewables to their full efficiency. Enter startup RheEnergise.

RheEnergise’s High-Density Hydro system pumps a special, hi-tech fluid uphill between storage tanks at times of low energy demand and cost. As energy prices rise, the fluid is released downhill through turbines, which generates electricity to supply the grid. 

RheEnergise’s mineral-rich fluid is two and a half times denser than water, which is normally used in pumped hydropower. As a result, it contains two and a half times the energy and can be used on a hill that is two and a half times smaller. This means the RheEnergise system does not need high mountains to work, leading to more potential sites and substantial reductions in construction costs.

RheEnergise recently received a £1 million grant (about €1.1 million) from the UK Government’s Net Zero Innovation Portfolio. It will use this investment to explore whether minerals or waste materials that do not need to be imported can be used in its fluid. 

The company plans to deploy a demonstrator close to Plymouth by the middle of next year. It is also pursuing other opportunities across the UK and Europe and expects to have its first five-megawatt grid-scale project in operation as early as 2026. RheEnergise has estimated that there are around 6,500 sites in the UK alone that could use the system.

Springwise has spotted other innovations utilising hydropower, including small turbines for use in any river, and a generator that works where fresh water meets the sea.

Written By: Jessica Bradley