Sage Geosystems, a Houston geothermal startup, is launching EarthStore, a geothermal energy storage project that will produce clean electricity on demand. To do so, the company entered into a land use agreement with San Miguel Electric Cooperative Inc. (SMECI) for a 3-megawatt (MW) geopressured geothermal storage facility.
Christine, Texas, will be the site of EarthStore, which will open later this year just outside of San Antonio, near the SMECI lignite coal power plant.
Sage Geosystems plans to buy and sell electricity to the ERCOT grid — Texas’ power grid. It has been faltering in recent years, unable to deal with more extreme winters and even hotter summers. This technology offers a reliable and resilient power source independent of weather conditions and not reliant on wind or sunshine.
“Once operational, our EarthStore facility in Christine will be the first geothermal energy storage system to store potential energy deep in the earth and supply electrons to a power grid,” Cindy Taff, CEO of Sage Geosystems, said in an August press release.
Graphic Courtesy Sage Geosystems
The facility will aim for a six-to-10-hour storage duration. It hopes to deliver an efficiency of 70–75% and targets a water loss of less than 2%. The facility will also be paired with other renewable sources to support ERCOT.
It’s cost-effective, too. EarthStore can deliver round-the-clock electricity for under 10 cents a kilowatt-hour.
“Long-duration energy storage is crucial for the ERCOT utility grid, especially with the increasing integration of intermittent wind and solar power generation,” Craig Courter, CEO of San Miguel Electric Cooperative, said in a statement.
“We are excited to be part of this innovative project that showcases the potential of geothermal energy storage.”
The company still needs Texas drilling permits for Atascosa and Starr counties, where the EarthStore facility and the company test well sit, respectively.
Additionally, Sage Geosystems entered into an agreement with Meta for expanded geothermal power use. The partnership will continue Mark Zuckerberg’s company’s investment in carbon-free energy for its data centers and to make the grid more reliable. The company claims this effort will be the “first use of next-generation geothermal power east of the Rocky Mountains.”
Phase 1 of the project is expected to come online in 2027. The deal was announced at the U.S. Department of Energy’s (DOE) Catalyzing Next Generation Geothermal Development Workshop on Aug. 26.
“We are thrilled to be at the forefront of the next generation of geothermal technology and applaud the DOE for supporting the commercialization of innovation solutions,” Taff said. “As energy demand continues to grow, the need for reliable, resilient, and sustainable power is paramount, and our partnership with Meta underscores the critical need for innovative and sustainable energy solutions like ours.”
