How does this new system work?
Think of the hill or slope as a natural ‘battery’ for the energy to be produced and stored in.
Water is moved uphill via pumps, and later released back down through turbines. These turbines spin, which generates electricity when needed. The key difference for this high intensity version is that it will use mineral-rich fluid that’s nearly three times as dense as water. This means smaller hills with less steep gradients can be used to produce much more energy.
Underground storage tanks larger than Olympic size swimming pools will house the fluid when it’s not in use, and surplus energy from the turbines will push the water back uphill. It’s all self-contained, making it an excellent energy source – no need for nasty, daily carbon emissions.
What happens next?
RheEnergise is the company heading the project.
It has claimed that this could allow for 700 new sites, totalling over 7GW of energy storage. For context, the UK is expected to need around 13GW of flexible clean energy generation and storage by 2030 in order to balance the electricity grid sustainably.
The company’s chief executive Stephen Crosher also says each site could be built within one or two years, which is five times faster than traditional hydropower systems. The first plant is planned to be built by mid-2023 and crowdfunding is already underway.
The first few will be put together in disused mines and quarries with sufficient space, though the eventual plan is to move them closer to solar and wind farms where they’ll be buried in hillsides and invisible to the naked eye. They’ll likely go down a lot better with locals than wind turbines did back in the day.
We’ll have to see whether or not these hill systems take off. Anything that gets us closer to a fully renewable UK the better.