US startups are pioneering the use of hydraulic fracturing technology to develop pressurized water energy storage systems, a promising alternative to traditional energy storage methods like lithium-ion batteries. This innovative approach utilizes underground pressurized water reservoirs to store energy generated from renewable sources such as wind and solar. Companies like Sage Geosystems, Fervo Energy, and Quidnet Energy are at the forefront of exploring various techniques within this domain to offer more cost-effective and widely deployable energy storage solutions.
As the reliance on renewable energy increases, particularly in states like Texas which leads in oil production, the necessity for robust energy storage solutions becomes paramount. These pressurized water energy storage systems ensure that clean energy is available on demand, regardless of the natural variability of wind and solar power. This technology is gaining attention for its potential to provide long-duration energy storage, which is crucial for maintaining a stable and reliable power grid.
Among the startups, Sage Geosystems has made significant strides with its EarthStore facility, which capitalizes on energy harvested from pressurized water energy storage deep underground. The system demonstrated its capability in a commercial pilot in Texas, where it successfully generated power for extended periods—200 kW for over 18 hours and 1 MW for 30 minutes—using Pelton turbines. With a roundtrip efficiency of 70-75% and minimal water losses, this technology not only supports the integration of intermittent renewable energy sources but also provides baseload, dispatchable power, and grid inertia.
Sage Geosystems recently announced the location of its new project in Christine, Texas, near the SMECI lignite coal power plant, emphasizing its role in the ERCOT grid where it will operate as a merchant to buy and sell electricity. The company’s CEO, Cindy Taff, highlighted the viability of geothermal pressurized water energy storage as a solution for both long and short-duration storage needs, positioning it as an alternative to short-duration lithium-ion batteries.
Fervo Energy and Quidnet Energy are also making notable advancements in this field. Fervo Energy has developed the FervoFlex technology, which utilizes a unique horizontal well design paired with hydraulically conductive fractures to enable multi-day pressurized water energy storage capabilities. This approach not only allows for the storage of large amounts of energy but also ensures the delivery of clean, firm geothermal power. Meanwhile, Quidnet Energy is working on a modified pumped hydro system called Geomechanical Pumped Storage, which involves pumping water under high pressure into confined rock formations, effectively using the subsurface as a durable energy storage reservoir.
These developments represent a significant shift towards utilizing hybrid technologies that blend traditional oil and gas infrastructure with renewable energy innovations. The reduced intensity of the fracking process used in these technologies, as noted by Sage’s Chief Geoscientist Mike Eros, signifies a less invasive approach, making it more environmentally acceptable and potentially a game-changer in the energy storage sector. Dubbed as “Earth batteries,” these systems are set to play a crucial role in integrating large-scale renewable energy solutions into the grid, paving the way for a more sustainable and energy-secure future.
https://oilprice.com/Energy/Energy-General/US-Startups-Use-Fracking-Tech-to-Store-Clean-Energy.html