Their work could result in many hundreds of hills across the UK being used to store renewable energy, acting as giant batteries.
This pioneering hydropower system embedded underground could see the unlocking of hundreds of potential hydropower sites across the UK, making it easier and less expensive to develop than traditional hydropower dams while having significantly less of an environmental impact.
These hillside projects are intended to mimic traditional hydropower plants by using surplus electricity to pump water uphill, then releasing it through turbines to generate electricity when needed.
These “high-intensity” hydro projects have been designed to use a mineral-rich fluid, which has more than two and a half times the density of water, to create the same amount of electricity from slopes which are less than half as high.
RheEnergise, the company behind the project, said it would be possible to pump the dense fluid up a hill with a height of 200 metres, at times of low electricity demand where it would be stored in an underground storage tank, larger than an Olympic swimming pool.
This project could open up around 700 sites across the country that would be able to play host to these new high-intensity hydro projects, which in theory could create a total of 7GW of energy storage to help the UK use more renewable electricity.
The UK is expected to need around 13GW of flexible clean energy generation and storage to help balance the electricity grid by the end of the decade, according to a report by Aurora Energy Research.
According to Stephen Crosher, chief executive of RheEnergise, these high-intensity hydro projects could be built in one to two years, and the company is looking to build projects of about 10MW at disused mines and quarries, located near wind and solar farms.
The first plant could appear by 2023 and a pilot is being planned, in a project that could help accelerate the UK's adoption of renewable energy.
