Proven Technology
Underground Pumped Storage Hydropower
Well established energy storage technology merged with modern deep underground construction techniques.
INNOVATIVE ENERGY STORAGE SOLUTIONS
Energy Storage required in California
Storage required to provide overnight renewable energy
Million metric tons of CO2 emissions per year from generation of electricity in California
Goal for California SB 100 requiring supply of 100% zero carbon and renewable energy
Maxwell Energy Storage Project
High-Head Underground Pumped Storage Project
1 - mile below surface
Large Hydraulic Head
The potential energy of a pumped storage plant is directly proportional to the elevation difference between reservoirs. Placing the Lower Reservoir underground allows a 4x increase in power versus a conventional pumped storage plant.
Low Environmental Impact
Underground Reservoir
The combination of a placing the lower reservoir underground and achieving a hydraulic head of ~1 mile results in much less surface disturbance and water use versus a conventional pumped storage plant.
US Department of Energy - 2023 Long Duration Energy Storage Report
Energy storage is essential to enabling utilities and grid operators to effectively adopt and utilize the nation’s growing portfolio of clean energy resources, like solar and wind, on demand. However, today’s energy storage technologies are not sufficiently scaled or affordable to support the broad use of renewable energy on the grid. Cheaper, longer, and more efficient storage is needed to meet energy demand that fluctuates throughout the day and night.