UK start-up RheEnergise promises to solve the issue of cost-effectively storing energy from intermittent sources such as solar and wind through an innovative, environmentally friendly approach that is significantly cheaper than battery storage. It is based on the proven concept of pumped hydro storage, which sees water moved between reservoirs located at different heights. When energy costs are low (such as when renewables are operating), water is pumped to the top storage tanks. As demand and prices rise this water is released, passing downhill through turbines, regenerating electricity to supply power to the grid.
RheEnergise’s High-Density Hydro solution uses the company’s proprietary HD Fluid R-19, which has two and a half times the density of water. This gives RheEnergise pumped energy storage projects the same increment of power and energy when compared to water, enabling them to be both significantly smaller and located on lower hills, minimising cost, environmental impact and providing 3-4 times greater availability of sites for construction. In addition, because projects are much smaller, High-Density Hydro can use buried tanks rather than huge open reservoirs.
Projects will be able to provide between 10MW-50MW of power and 2-10 hours of storage capacity, depending on the size of project. According to the company, energy costs will be more than 40% below lithium-ion battery technology for medium duration projects (3+ hours). The company expects projects to be built close to demand, such as near cities or large energy users (for example industrial estates) to help local authorities and businesses meet their growing requirements for greener electricity, or co-located with renewable sources such as wind or solar farms. They will also provide a green source of energy for electric vehicle battery recharging which is likely to be an extra burden on the grid over time.
Eminox will provide the control systems for the project, managing the flow of the HD Fluid R-19 between tanks, the pump turbine and generator operations, monitoring sensors and interfacing with the local electricity grid to manage power supply.
Dave Phillips, engineering director, Eminox, says: “Our work on this project is an example of how we are using our experience and expertise from emission control solutions and applying them successfully to solve real-world problems as we move towards a zero carbon economy across the globe. This demonstrates our abilities to help both new innovators and our existing automotive customers as they embrace electric and hybrid vehicles, powered by electricity that has been generated and stored in a much greener manner.”
Supported by multiple grants from the UK government, RheEnergise has created and tested the overall architecture of its solution, and is currently fundraising in order to build a scale demonstrator of its technology, ahead of full-scale commercialisation. It has already achieved over 175% of its initial £100,000 investment target through crowdfunding site Crowdcube.
“Having a partner such as Eminox on-board will help us accelerate our development and deliver on the promise of our technology, and successfully compete against both battery energy storage and gas peaking plants,” said Stephen Crosher, CEO and Founder, RheEnergise. “In many ways our solution has numerous similarities to an engine emissions system, with multiple inputs, outputs and complex fluid flows – that makes its expertise perfect for delivering a control system that can manage our exacting requirements.”