Sage Snags Air Force Contract for Geothermal Power Demonstration in Texas
The U.S. Department of the Air Force has awarded Sage Geosystems an initial $1.9 million contract to demonstrate its pioneering geothermal baseload power and energy storage system at an off-site test well in Starr County, Texas.
When completed as planned in 2025, the demonstration will become the first Geopressured Geothermal Systems (GGS) facility in the world to generate power, Sage said on Sept. 24. The project is slated to help the Air Force “determine whether a power plant using [GGS] can generate the clean energy needed for a base to achieve energy resilience,” it said.
The Air Force is exploring the possibility of installing a full-scale project at Ellington Field Joint Air Reserve Base in Houston. “This initial contract is a step forward in the Air Force’s push for energy resilience,” said Kirk Phillips, Director of the Air Force Office of Energy Assurance, in a statement.
“This project will improve Ellington Field’s ability to maintain operations during electrical grid outages and be completely self-sufficient for their energy needs. This project, and the future Department of the Air Force projects that it paves the way for, will help to assure that our national security needs are met by our installations during critical emergencies.”
An Underground Geothermal Battery
Sage will match the Air Force’s grant with an additional $1.9 million for the demonstration project. The contract marks more ground for the Houston-based startup founded in 2020 by oil and gas industry veterans.
As POWER has explained in detail, Sage’s system uses gravity fracking to store energy by injecting water into a fractured low-permeability rock formation during low demand and later releasing the pressurized water to drive a Pelton turbine for electricity generation when needed. “Unlike traditional geothermal techniques that rely on rare geological formations of hot water and steam that limit their use, GGS repurposes cutting-edge fracking technology to extract thermal energy from miles below the Earth’s surface,” the company noted on Tuesday.
The demonstration is one of three geothermal pilot projects the Air Force has kicked off this year. The Joint Base San Antonio (JBSA) has been working with Eavor, Teverra, and Zanskar Geothermal and Minerals to install a prototype of Eavor’s closed-loop geothermal technology at its facility in Texas. Eavor’s Eavor-Loop connects two vertical wells with many horizontal multilateral wellbores to create a closed-sealed radiator-like system that uses a proprietary working fluid.
The Department of Defense (DOD) is in tandem exploring novel geothermal technologies developed by Fervo Energy and GreenFire Energy. Fervo is exploring enhanced geothermal system (EGS) potential at Naval Air Station Fallon in Nevada. GreenFire will explore the potential of its closed-loop advanced geothermal system (AGS) at Naval Air Facility El Centro in California. Sage is separately exploring the potential to deploy its proprietary GGS technology at Fort Bliss in Texas for the U.S. Army and the Defense Innovation Unit (DIU).
The Air Force calls its exploration of cutting-edge geothermal technology a “force multiplier.” “We are in an era of strategic competition with China, which means that our installations are no longer a sanctuary from the full spectrum of threats,” said Dr. Ravi Chaudhary, assistant secretary of the Air Force for Energy, Installations, and Environment, last year. “We need to ruggedize our installations with redundant energy systems and make use of clean energy sources that reduce our fuel demands. Geothermal sources strengthen our energy grids and give us the ability to isolate threats before they impact our operations. This type of capability will translate into victory in a high-end fight.”
“We would build geothermal energy power plants at every Air Force installation if we could,” Phillips said on Tuesday. “Geothermal power is renewable, it is secure, it is reliable, it is cost-effective, and the systems to produce power from heat are well-understood.”
Air Force Project Follows Agreement With Meta for Data Center Power
For Sage, the prospect of its first power project marks another crucial notch in its quickly progressing efforts to commercialize its technology. Alongside its military contracts, the company has sought to demonstrate how GGS could provide grid flexibility. In August, it said it would build its first 3-MW “underground battery” on land owned by San Miguel Electric Cooperative in Christine, Texas. The company plans to begin operating the project later this year to supply the Electric Reliability Council of Texas (ERCOT) grid.
Later in August, Sage unveiled an agreement with social technology giant Meta (formerly Facebook) to deploy 150 MW of geothermal baseload power to support Meta’s data center growth. The first phase of the project could come online in 2027.
“Advanced geothermal energy is currently mainly used in Nevada, Utah, and California. Sage’s technology marks a significant advancement for the clean energy sector, showcasing the ability to harness geothermal energy virtually anywhere and promising a new era of reliable, sustainable baseload power and enhanced grid stability,” Meta said. “Hot dry rock is a vastly abundant resource compared to traditional hydrothermal formations, making Sage’s GGS technology a highly scalable approach with the potential for rapid expansion across the U.S. and globally.”
—Sonal Patel is a POWER senior editor (@sonalcpatel, @POWERmagazine).