1
Country: USA | Funding: $31.3M
Quidnet Energy develops long-duration geomechanical energy storage systems. This new form of underground pumped-storage hydroelectric power generation utilizes existing natural resources. Each module is manufactured using traditional drilling processes and standardized hydromechanical energy conversion components. The modules operate within a closed-loop water system designed to prevent energy loss through evaporation. When excess power is available, it is used to pump water from a pond into a borehole, maintaining it under pressure. The borehole is then closed, maintaining the stored energy under pressure for as long as needed. When power is needed, the borehole is opened, allowing the pressurized water to pass through a turbine to generate electricity and return to the pond for the next cycle.
Quidnet Energy develops long-duration geomechanical energy storage systems. This new form of underground pumped-storage hydroelectric power generation utilizes existing natural resources. Each module is manufactured using traditional drilling processes and standardized hydromechanical energy conversion components. The modules operate within a closed-loop water system designed to prevent energy loss through evaporation. When excess power is available, it is used to pump water from a pond into a borehole, maintaining it under pressure. The borehole is then closed, maintaining the stored energy under pressure for as long as needed. When power is needed, the borehole is opened, allowing the pressurized water to pass through a turbine to generate electricity and return to the pond for the next cycle.
2
Country: UK | Funding: £14M
ReEnergise developed High-Density Hydro technology to create pumped hydro energy storage systems that can be located in low-lying, hilly terrain, eliminating the need for high, steep slopes. The HD Hydro system uses a dense, mineral-rich liquid instead of water to reduce the system's size while delivering the same performance as a much larger system using regular water. The liquid recirculates through a pipeline between the upper and lower reservoirs. The compact size of the HD Hydro system allows for burying one or both reservoirs underground, preserving the land above for other uses. With an eight-hour operating cycle, this high-density hydropower system is half the cost of a lithium-ion battery system, without the risk of fire or environmental concerns. The company has already implemented a pilot project at Cornwood, a kaolin mine in the UK.
ReEnergise developed High-Density Hydro technology to create pumped hydro energy storage systems that can be located in low-lying, hilly terrain, eliminating the need for high, steep slopes. The HD Hydro system uses a dense, mineral-rich liquid instead of water to reduce the system's size while delivering the same performance as a much larger system using regular water. The liquid recirculates through a pipeline between the upper and lower reservoirs. The compact size of the HD Hydro system allows for burying one or both reservoirs underground, preserving the land above for other uses. With an eight-hour operating cycle, this high-density hydropower system is half the cost of a lithium-ion battery system, without the risk of fire or environmental concerns. The company has already implemented a pilot project at Cornwood, a kaolin mine in the UK.
3
Country: Italy | Funding: $8M
Sizable Energy creates offshore pumped-storage hydroelectric power plants. Their modular, scalable ocean-based system enables low-cost long-term energy storage on a gigawatt scale by pumping saturated seawater brine (which is heavier than seawater) from the seafloor to a surface reservoir, harnessing the ocean's depth. In recovery mode, the brine flows downward under the influence of gravity, turning a power turbine. The design is simple and includes reservoir on the ocean floor, another floating on the surface, connecting pipe and reversible pumping turbines to pump the saturated seawater brine between the two reservoirs. The system is made from readily available materials that can be manufactured, assembled and installed at depths of 500 meters or more using existing offshore infrastructure. It can be linked to floating wind and solar power plants. Since only ocean water is used, the solution is environmentally sustainable.
Sizable Energy creates offshore pumped-storage hydroelectric power plants. Their modular, scalable ocean-based system enables low-cost long-term energy storage on a gigawatt scale by pumping saturated seawater brine (which is heavier than seawater) from the seafloor to a surface reservoir, harnessing the ocean's depth. In recovery mode, the brine flows downward under the influence of gravity, turning a power turbine. The design is simple and includes reservoir on the ocean floor, another floating on the surface, connecting pipe and reversible pumping turbines to pump the saturated seawater brine between the two reservoirs. The system is made from readily available materials that can be manufactured, assembled and installed at depths of 500 meters or more using existing offshore infrastructure. It can be linked to floating wind and solar power plants. Since only ocean water is used, the solution is environmentally sustainable.
4
Country: USA | Funding: $6.5M
Sperra manufactures subsea pumped-storage hydroelectric power plants integrated with offshore energy storage systems. The company has developed a multi-sphere "capsule" design, localized production using automated 3D concrete printing and integration with offshore renewable energy sources to share infrastructure and reduce costs. Sperra's SPSH systems consist of 2-5 MW modules in US ports using local materials and labor. They operate by moving water in and out of large concrete spheres on the ocean floor to store and release energy as needed. Modules can be installed independently along coastlines or adjacent to offshore wind farms to save money and generate additional revenue.
Sperra manufactures subsea pumped-storage hydroelectric power plants integrated with offshore energy storage systems. The company has developed a multi-sphere "capsule" design, localized production using automated 3D concrete printing and integration with offshore renewable energy sources to share infrastructure and reduce costs. Sperra's SPSH systems consist of 2-5 MW modules in US ports using local materials and labor. They operate by moving water in and out of large concrete spheres on the ocean floor to store and release energy as needed. Modules can be installed independently along coastlines or adjacent to offshore wind farms to save money and generate additional revenue.
5
Country: Estonia | Funding: €2M
Zero Terrain developed technology for pumped-storage hydroelectric power plants that allows them to be built on flat terrain without mountains that typically used for such projects. The technological innovation of Zero Terrain's solution lies in the placement of the lower reservoirs of the pumped-storage in the earth's crust with favorable geological conditions and the use of surface water bodies as upper reservoirs. Earth beams are used as the building structure, reducing the use of construction materials and the impact on land use. The modular design allows for increased storage capacity at a lower cost than any existing alternative. Low use of critical materials reduces supply risks. The company operates its own 500 MW hydroelectric storage facility, Energiasalv, in Estonia. During its nominal operating cycle of 30 hours, Energiasalv supplies 15 million kWh to the grid.
Zero Terrain developed technology for pumped-storage hydroelectric power plants that allows them to be built on flat terrain without mountains that typically used for such projects. The technological innovation of Zero Terrain's solution lies in the placement of the lower reservoirs of the pumped-storage in the earth's crust with favorable geological conditions and the use of surface water bodies as upper reservoirs. Earth beams are used as the building structure, reducing the use of construction materials and the impact on land use. The modular design allows for increased storage capacity at a lower cost than any existing alternative. Low use of critical materials reduces supply risks. The company operates its own 500 MW hydroelectric storage facility, Energiasalv, in Estonia. During its nominal operating cycle of 30 hours, Energiasalv supplies 15 million kWh to the grid.
