British company RheEnergise has invented a low-cost, energy efficient and environmentally-benign energy storage solution designated ‘High-Density Hydro’, and is currently undertaking its first crowdfunding campaign to fund the next phase of its work. The project has been part-funded by Innovate UK, an arm of the UK government (eight grants totalling £550,000 to December 2020 and a further on-going grant of £135,000), and supported by a number of academic and research organisations, including Exeter University.

RheEnergise is aiming to have its first commercial system operating in 2024 and over 100 systems within the next decade. At the heart of the technology is a newly invented high density fluid – designated R-19 – which is 2.5 times denser than water, and can therefore provide 2.5 times the energy, from the same difference in elevation, compared to a conventional hydro-power system of the sort that is in operation around the world.

The prospect is to pump the fluid uphill between storage tanks that are buried underground, as with conventional storage, but because of the new fluid the system can operate beneath small hills rather than mountains.

RheEnergise’s analysis suggest that there are about 9500 site opportunities in the UK, 80 000 in Europe and 160 000 in Africa.

It is acknowledged that far more energy storage will be required in the future to support the UK energy system and globally.  In the UK, Aurora Energy Research forecasts an additional 13GW storage requirement by 2030 (it is currently 3.8GW).  Whilst Bloomberg New Energy Finance predicts that the global energy storage market needs to grow 100 times its current size and will be worth in excess of US$620 bn by 2040. 

RheEnergise’s R&D work to date has been part-funded by Innovate UK and supported by universities as well as the Science & Technology Facilities Council, the National Engineering Laboratory and Eminox, a specialist engineering company.

 “Whilst our underground, hillside technology opens up a massive amount of opportunity, we acknowledge the need for careful planning and stringent environmental assessments. Not every hillside location will be suitable.”