An energy-storage system made up of a series of tanks filled with a special liquid achieved full capacity on a hilltop in southwest England. Unlike systems based on normal water, this one uses a heavy, proprietary liquid as part of its High-Density Hydro system. UK-based company RheEnergise built the 500kW demonstration system on a small hill near Cornwood in Devon.
The goal was to see how well its “High-Density Hydro” technology worked in real-world environments.
The result would provide the company with its clearest indication yet of whether the design could move beyond the testing stage.
Success could influence whether larger commercial-scale projects move forward in the U.K. and abroad.
What mattered was proving it could work
The 500kW demonstration version of the High-Density Hydro system is the first actual working example of this type of energy storage system. The facility received funding from the U.K. government’s Net Zero Innovation Portfolio program. It is located close to the Cornwood Mine owned by Sibelco, which is a major source of kaolin clay used in ceramics and sanitary ware.
According to RheEnergise, the project is also helping support the site’s operations during periods of high energy demand. The company says the system could also support efforts to decarbonize industrial activity at the site.
The plant demonstrated sustained operation at a 500-kW peak output, with its final configuration capable of running for roughly 15 minutes at full power.
RheEnergise says reaching full power demonstrated that the technology can operate under real-world conditions.
The hills no longer need to be mountains
Typically, traditional pumped hydroelectric storage systems require significant elevation changes.
For that reason, they are usually only viable options in mountainous areas.
RheEnergise says this ability is made possible by the properties of the fluid they use. Rather than simply relying on water like most other gravity-based storage systems, the company uses a specially formulated liquid called R19. R19 is a heavier liquid than water.
Because of that property, they say their system can produce comparable amounts of power on hillsides that are roughly two-and-a-half times shorter than hillsides that are required by conventional pumped hydroelectric systems.
More places could become viable
This could open up several additional potential sites for building new facilities. Additionally, RheEnergise says that their system is designed so that facilities can be installed closer to where the electricity is needed.
They say that R19 has a higher energy density than water. In another report from RheEnergise, the company said that using R19 can reduce the need for water storage.
The company notes that R19 has been independently tested and verified as non-toxic. Furthermore, each facility includes safety features such as leak detection and containment mechanisms.
Devon was only the real starting point
Achieving full power status does not necessarily indicate that the technology has been successfully scaled up to commercial levels. The company states that achieving full-power status at the Devon facility represents a key milestone in demonstrating the feasibility of the technology.
It also says the project has provided evidence to support development plans for larger long-duration energy storage systems. These larger projects are planned to be in the 10-100MW range.
Commercial projects are now the target
RheEnergise is evaluating potential sites in Italy, Poland and Spain for future High-Density Hydro facilities. The company says it aims to have its first commercial-scale project in operation within three years. It is now pursuing commercial-scale projects in the UK, continental Europe and North America.
The successful testing of a gravity-based energy storage system using a fluid denser than water has demonstrated that such systems can be fully powered on hillsides. That could allow future deployments in locations without access to the mountainous terrain typically associated with pumped hydropower.
Read the whole thing?
Get the week's signal, not the noise
Our sharpest reporting on energy, climate and nature — free, once a week.
