Sage selects Texas site for 3-MW geothermal energy storage project

US geothermal technology developer Sage Geosystems Inc announced it has secured a site in the town of Christine, Texas, to build a 3-MW geopressured geothermal system (GGS) energy storage facility, expecting to launch the project later this year.

The company said it had entered into a land use agreement with the South Texas power generation and transmission cooperative, San Miguel Electric Cooperative Inc (SMECI), seeking to use a site near the SMECI lignite coal-fired power plant in Christine for its GGS project.

Sage’s planned facility, called EarthStore, will use the company's proprietary technology to harness the earth’s potential to store energy deep in the underground. According to the developer, the EarthStore system is designed to store energy for a period of six to ten hours and target a round-trip efficiency of 70%-75%. As the system uses pressurised water as a storage medium, Sage claims that water losses can be kept to below 2%.

Sage envisions combining its storage system with renewable sources like solar power to create a consistent and reliable power supply. The combined system of solar power and the EarthStore energy storage is expected to produce electricity at a blended levelised cost of energy of less than USD 0.10 per kilowatt-hour (EUR 0.091/kWh), Sage said.

The company will function as a merchant for the EarthStore facility, buying and selling electricity to the ERCOT grid. It says it has applied for two drilling permits in Texas -- one in Atascosa County for the EarthStore facility in Christine, while the second permit is in Starr County, adjacent to its existing test well.

Earlier this year, Sage raised USD 17 million in a Series A financing round to advance the EarthStore project.

“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,” said Cindy Taff, CEO of Sage Geosystems. “Geothermal energy storage is a viable solution for long-duration storage and an alternative for short-duration lithium-ion batteries. Electric utilities and co-ops like SMECI, will be able to use our technology to complement wind and solar, and stabilize the grid.”

(USD 1.0 = EUR 0.908)

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