Sage Geosystems brings South Texas geothermal plant online

powering up

Sage Geosystems' South Texas facility is ready to generate and supply electricity to the grid. Photo courtesy Sage Geosystems

Houston-based Sage Geosystems, a provider of geothermal power, has begun full operations at its South Texas facility for the San Miguel Electric Cooperative.

Sage says the plant was recently “placed in service,” according to a news release. This means it’s fully built and tested, and ready to generate and supply electricity to the grid.

Since selling its first electricity in Q2 of this year, the facility has been operating for more than four months to evaluate aspects like efficiency and water management. Sage relied on its GeoTwin modeling tool to carry out some of the testing.

The testing demonstrates Sage’s proprietary approach to geothermal power “overcomes one of the industry’s most persistent challenges, high water losses in engineered reservoirs, while delivering the consistent performance required to scale next-generation geothermal,” co-founder and CEO Cindy Taff said in the release.

Sage says the South Texas facility will serve as a model for future projects, including one in Nevada. The Nevada facility will use Sage’s proprietary technology to extract geothermal heat from hot dry rock, creating a reliable, affordable source of carbon-free power.

During the testing period, water losses amounted to less than 10 percent. This low rate indicates most water remains in the system, enabling Sage to capture more usable energy, boost power production and improve the project’s finances, the company says.

“Commercial geothermal isn’t just about creating a reservoir. It’s about creating one whose performance can be engineered, predicted, and consistent,” Lev Ring, the company’s co-founder, president and chief technology officer, said in the release.

Since being founded in 2020, Sage has raised $159 million in outside funding. This includes a more than $97 million Series B round co-led by Ormat Technologies and Carbon Direct Capital.

Two years ago, Sage announced a deal with Meta Platforms, the parent company of Facebook and Instagram, to supply up to 150 megawatts of geothermal power to Meta data centers.

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Sage Geosystems has raised a $97 million Series B. Photo via sagegeosystems.com.

Houston geothermal company raises $97M Series B

fresh funding

Houston-based geothermal energy startup Sage Geosystems has closed its Series B fundraising round and plans to use the money to launch its first commercial next-generation geothermal power generation facility.

Ormat Technologies and Carbon Direct Capital co-led the $97 million round, according to a press release from Sage. Existing investors Exa, Nabors, alfa8, Arch Meredith, Abilene Partners, Cubit Capital and Ignis H2 Energy also participated, as well as new investors SiteGround Capital and The UC Berkeley Foundation’s Climate Solutions Fund.

The new geothermal power generation facility will be located at one of Ormat Technologies' existing power plants. The Nevada-based company has geothermal power projects in the U.S. and numerous other countries around the world. The facility will use Sage’s proprietary pressure geothermal technology, which extracts geothermal heat energy from hot dry rock, an abundant geothermal resource.

“Pressure geothermal is designed to be commercial, scalable and deployable almost anywhere,” Cindy Taff, CEO of Sage Geosystems, said in the news release. “This Series B allows us to prove that at commercial scale, reflecting strong conviction from partners who understand both the urgency of energy demand and the criticality of firm power.”

Sage reports that partnering with the Ormat facility will allow it to market and scale up its pressure geothermal technology at a faster rate.

“This investment builds on the strong foundation we’ve established through our commercial agreement and reinforces Ormat’s commitment to accelerating geothermal development,” Doron Blachar, CEO of Ormat Technologies, added in the release. “Sage’s technical expertise and innovative approach are well aligned with Ormat’s strategy to move faster from concept to commercialization. We’re pleased to take this natural next step in a partnership we believe strongly in.”

In 2024, Sage agreed to deliver up to 150 megawatts of new geothermal baseload power to Meta, the parent company of Facebook. At the time, the companies reported that the project's first phase would aim to be operating in 2027.

The company also raised a $17 million Series A, led by Chesapeake Energy Corp., in 2024.

In a recent Energy Tech Startups Podcast episode, Cindy Taff discussed the evolution of Sage GeoSystems, the challenges of scaling hard tech solutions, and the opportunities presented by geothermal and pumped hydro energy storage. Photo courtesy of Sage

Houston founder on driving the future of geothermal energy, storage

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Cindy Taff, co-founder and CEO of Sage GeoSystems, has emerged as a visionary leader in the energy transition, recently named to Time magazine’s 100 Most Influential Climate Leaders in Business for 2024. Under her leadership, Sage is not only advancing geothermal energy innovation but also redefining how energy storage can support a renewable-powered grid.

In a recent Energy Tech Startups Podcast episode, Taff discussed the evolution of Sage GeoSystems, the challenges of scaling hard tech solutions, and the opportunities presented by geothermal and pumped hydro energy storage. Her insights reflect the unique perspective of a founder bridging oil and gas expertise with renewable energy innovation.

- YouTubeCindy shares how Sage Geosystems is leveraging its oil and gas expertise to develop groundbreaking subsurface pumped hydro ...

Breaking Boundaries with Geopressured Geothermal Systems

Sage GeoSystems is at the forefront of next-generation geothermal energy, advancing Geopressured Geothermal Systems (GGS) that can be deployed in a wide range of geographies. Unlike traditional geothermal systems, which rely on natural water reservoirs near volcanic activity, Sage’s engineered reservoirs allow geothermal energy to be tapped almost anywhere.

“Geothermal energy is no longer restricted to specific conditions,” Taff explained. “Our systems are flexible, scalable, and capable of meeting the needs of energy-intensive applications like data centers—including a recent deal with Meta to deliver 150 megawatts of geothermal power for their facilities.”

This adaptability sets Sage apart, offering a path to reliable, clean energy that can complement intermittent sources like wind and solar. Sage also secured a win in the Energy Transition Business category alongside notable finalists like Amperon and Tierra Climate, underscoring its leadership in innovative energy solutions.

Pivoting Toward Subsurface Energy Storage

While initially focused solely on geothermal, Sage uncovered a transformative opportunity in subsurface pumped hydro energy storage during field trials. Dubbed “upside-down pumped hydro,” the solution provides long-duration energy storage capable of balancing the grid for 17+ hours—far surpassing the capabilities of lithium-ion batteries for extended periods.

“Pumped storage hydropower is a critical piece of the energy puzzle,” Taff emphasized. By storing energy during off-peak times and releasing it when solar and wind aren’t producing, Sage is helping bridge the intermittency gap in renewables. This approach positions pumped storage as a game-changer for a reliable, clean energy grid.

Lessons from the Founder’s Journey

Taff’s transition from a 35-year career at Shell to geothermal entrepreneurship offers valuable lessons for founders in capital-intensive industries:

Leverage Expertise, but Stay Open to New Solutions:
Taff’s oil and gas background enabled her to approach geothermal with deep technical knowledge, but Sage’s pivot to energy storage illustrates the importance of staying adaptable during development.
Educate Financial Stakeholders:
Securing funding for hard tech remains a challenge. “Investors often lack the subsurface knowledge needed to understand our technology,” Taff explained. She emphasized the need to bring on team members who can translate technical innovation into financial terms.
Be Ready for Capital-Intensive Scaling:
With geothermal plants costing millions to build, startups must carefully manage capital and timelines. Taff encourages founders to seek strategic investors, like Chesapeake Energy, who understand the challenges and potential of scaling infrastructure.

Beyond Geothermal: A Call for Pumped Storage Hydropower

In addition to geothermal, Taff champions pumped storage hydropower as an underutilized climate solution. “While lithium-ion batteries get a lot of attention, pumped storage hydropower offers long-duration storage that can stabilize the grid for days, not just hours,” she said.

By storing excess energy during off-peak times and releasing it when solar and wind aren’t producing, pumped storage hydropower can play a critical role in balancing renewables. Sage GeoSystems is uniquely positioned to integrate this technology into a broader energy strategy, offering sustainable and scalable solutions for energy-intensive industries.

A Vision for Geothermal and the Energy Transition

Looking ahead, Taff sees geothermal energy and storage as critical components of a sustainable energy mix. “We’re still in the early stages, but geothermal is following a trajectory similar to wind and solar 15 years ago,” she said. Sage’s innovative approaches are paving the way for geothermal to become a scalable, competitive solution, capable of powering industries and data centers while providing energy storage that stabilizes the grid.

With her recognition by Time magazine and a recent deal with Meta, Sage GeoSystems is proving that geothermal energy can be a powerful ally in achieving global decarbonization goals. The company’s innovative Geopressured Geothermal Systems and subsurface storage solutions are laying the groundwork for a reliable and sustainable energy future.

Listen to the full episode with Cindy Taff on the Energy Tech Startups Podcast here.

Energy Tech Startups Podcast is hosted by Jason Ethier and Nada Ahmed. It delves into Houston's pivotal role in the energy transition, spotlighting entrepreneurs and industry leaders shaping a low-carbon future.

These three Houston innovators have been recognized by Time Magazine. Photos courtesy

3 Houstonians named to prestigious list of climate leaders

who's who

Three Houston executives — Andrew Chang, Tim Latimer, and Cindy Taff — have been named to Time magazine’s prestigious list of the 100 Most Influential Climate Leaders in Business for 2024.

As managing director of United Airlines Ventures, Chang is striving to reduce the airline’s emissions by promoting the use of sustainable aviation fuel (SAF). Jets contribute to about two percent of global emissions, according to the International Energy Agency.

In 2023, Chang guided the launch of the Sustainable Flight Fund, which invests in climate-enhancing innovations for the airline sector. The fund aims to boost production of SAF and make it an affordable alternative fuel, Time says.

Chang tells Time that he’d like to see passage of climate legislation that would elevate the renewable energy sector.

“One of the most crucial legislative actions we could see in the next year is a focus on faster permitting processes for renewable energy projects,” Chang says. “This, coupled with speeding up the interconnection queue for renewable assets, would significantly reduce the time it takes for clean energy to come online.”

At Fervo Energy, Latimer, who’s co-founder and CEO, is leading efforts to make geothermal power “a viable alternative to fossil fuels,” says Time.

Fervo recently received government approval for a geothermal power project in Utah that the company indicates could power two million homes. In addition, Fervo has teamed up with Google to power the tech giant’s energy-gobbling data centers.

In an interview with Time, Latimer echoes Chang in expressing a need for reforms in the clean energy industry.

“Addressing climate change is going to require us to build an unprecedented amount of infrastructure so we can replace the current fossil fuel-dominated systems with cleaner solutions,” says Latimer. “Right now, many of the solutions we need are stalled out by a convoluted permitting and regulatory system that doesn’t prioritize clean infrastructure.”

Taff, CEO of geothermal energy provider Sage Geosystems, oversees her company’s work to connect what could be the world’s first geopressured geothermal storage to the electric grid, according to Time. In August, Sage announced a deal with Facebook owner Meta to produce 150 megawatts of geothermal energy for the tech company’s data centers.

Asked which climate solution, other than geothermal, deserves more attention or funding, Taff cites pumped storage hydropower.

“While lithium-ion batteries get a lot of the spotlight, pumped storage hydropower offers long-duration energy storage that can provide stability to the grid for days, not just hours,” Taff tells Time. “By storing excess energy during times of low demand and releasing it when renewables like solar and wind are not producing, it can play a critical role in balancing the intermittent nature of renewables. Investing in pumped storage hydropower infrastructure could be a game-changer in achieving a reliable, clean energy future.”

Clockwise from top left: Sean Kelly of Amperon, Dianna Liu of ARIXTechnologies, Matthew Dawson of Elementium Materials, Vibhu Sharma of InnoVent Renewables, Cindy Taff of Sage Geosystems, and Emma Konet of TierraClimate. Photos courtesy

Houston's top energy transition founders explain their biggest challenges

overheard

From finding funding to navigating the pace of traditional oil and gas company tech adoption, energy transition companies face their fair share of challenges.

This year's Houston Innovation Awards finalists in the Energy Transition category explained what their biggest challenge has been and how they've overcome it. See what they said below, and make sure to secure your tickets to the Nov. 14 event to see which of these finalists win the award.

"The evolving nature of the energy industry presents opportunities to solve some of our industry's greatest challenges. At Amperon we help optimize grid reliability and stability with the power of AI demand forecasting."

— Sean Kelly, CEO of Amperon, an AI platform powering the smart grid of the future

"The biggest challenge in leading an energy transition-focused startup has been balancing the urgency for sustainable solutions with the slow pace of change in traditional industries like oil and gas. Many companies are cautious about adopting new technologies, especially when it comes to integrating sustainability initiatives. We overcame this by positioning our solutions not just as environmentally friendly, but as tools that improve safety, efficiency, and cost savings. By aligning our value proposition with their operational goals and demonstrating real, measurable benefits, we were able to gain traction and drive adoption in industries that are traditionally resistant to change."

— Dianna Liu, CEO of ARIXTechnologies, an integrated robotics and data analytics company that delivers inspection services through its robotics platforms

"Scaling up production of hard tech is a major challenge. Thankfully, we recruited top-notch talent with experience in technology scale-up and chemical processes. In addition, we've begun building partnerships with some of the world's largest chemical manufacturers in our space who are excited to be a part of our journey and could rapidly accelerate our go to market strategy. We have significant demand for our product as early as 2025, so partnering with these companies to scale-up will bring our technology to market years ahead of doing it alone."

— Matthew Dawson, CEO of Elementium Materials, a battery technology with liquid electrolyte solutions

"Our pyrolysis reactor is a proprietary design that was developed during Covid. We ran simulations to prove that it works, but it was not easy to test it in a pilot facility, let alone scaling it up. We managed ... to run our pilot plant studies, while working with them remotely. We proved that our reactor worked and produced high quality products. Later, we built our own pilot plant R&D facility to continue running tests and optimizing the process. Then, there was the challenge of scaling it up to commercial size. ... We put together a task force of four different companies to come together to design and build this complex reactor in record time."

— Vibhu Sharma, CEO of InnoVent Renewables, a startup with proprietary continuous pyrolysis technology that converts waste tires, plastics, and biomass into valuable fuels and chemicals

"Energy storage and geothermal power generation are capital-intensive infrastructure projects, requiring investors with a deep commitment and the patience in terms of years to allow the technology to be developed and proven in the field. One challenge is finding that niche of investors with the vision to join our journey. We have succeeded in raising our $30 million series A with these types of investors, whom we’re confident will continue the journey as we scale."

— Cindy Taff, CEO of Sage Geosystems, an energy company focused on developing and deploying advanced geothermal technologies to provide reliable power and sustainable energy storage solutions regardless of geography

"The biggest challenge we've faced has been to bring together massive independent power producers on one side who are investing hundreds of millions of dollars into grid infrastructure with multi- national tech giants on the other that don't have experience working much with energy storage. As a startup with only four employees, gaining credibility with these players was critical. We overcame this hurdle by becoming the preeminent thought leader on storage emissions, through publishing white papers, discussing the issues on podcasts, and (more)."

— Emma Konet, CTO of TierraClimate, a software provider that helps grid-scale batteries reduce carbon emissions

Sage Geosystems will onboard its technology at the Naval Air Station in Corpus Christi. Photo via Naval Air Station Corpus Christi/Facebook

Houston geothermal co. expands DOD partnership with South Texas initiative

seeing green

Expanding on its partnership with the United States Department of Defense's Defense Innovation Unit, Sage Geosystems has been selected to conduct geothermal project development initiatives at Naval Air Station in Corpus Christi.

Along with the Environmental Security Technology Certification Program, Sage will provide its proprietary Geopressured Geothermal Systems technology, will be able to evaluate the potential for geothermal baseload power generation to provide clean and consistent energy at the Naval Air Station base.

“We’re pleased to expand our partnership with the DOD at NAS Corpus Christi to demonstrate the advantages of geothermal technology for military energy independence,” Cindy Taff, CEO of Sage Geosystems, says in a news release.

Sage is also conducting initiatives at Fort Bliss and has completed an analysis at the Ellington Field Joint Reserve Base. The analyses could “pave the way for expanding geothermal energy solutions across additional U.S. military installations,” according to Sage.

The company’s proprietary technology works by leveraging hot dry rock, which is a more abundant geothermal resource compared to traditional hydrothermal formations, and it provides energy resilience for infrastructures. In addition, Sage is building a 3 megawatt commercial EarthStore geothermal energy storage facility in Christine, Texas, which is expected to be completed by December. Sage also announced a partnership with Meta Platforms. With Meta Platforms, Sage will deliver up to 150 megawatt of geothermal power generation east of the Rocky Mountains.

The Naval Air Station Corpus Christi is considered a critical training and operations hub for the U.S. Navy, and the partnership with Sage shows the Navy's commitment to achieving net-zero carbon emissions by 2045. Sage’s technology will be assessed for its ability to create a microgrid, which can reduce reliance on the utility grid and ensure power supply during outages.

“As we advance our Geopressured Geothermal Systems, we see tremendous potential to not only provide carbon-free power, but also strengthen the operational capabilities of U.S. military installations in an increasingly digital and electric world,” Taff adds.

In September, the Air Force awarded Sage a grant of $1.9 million in a first-of-its kind contract to determine whether a power plant using Geopressured Geothermal Systems is able to generate clean energy needed for a base to achieve energy resilience.

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ENGIE inks deal to supply wind energy for Oracle’s Texas operations

wind deal

Houston-based renewable energy company ENGIE North America has made a deal to supply up to 568 megawatts of renewable electricity for tech giant Oracle's projects in Texas.

The power will come from ENGIE’s wind resources serving the Electric Reliability Council of Texas (ERCOT) grid. Oracle is developing data centers in Abilene and Shackelford, Texas, according to its website.

The Oracle deal is part of ENGIE’s efforts to bring substantial new electricity supply to the grid. In the past six years, ENGIE has developed 12 gigawatts of new renewable generation and battery storage capacity in North Americas, equaling $11 billion in capital, according to the company.

"Our customers are looking for reliable, scalable energy solutions that can support long-term growth," Anne-Laure Chassanite, interim CEO of ENGIE North America, said in a news release. "ENGIE has invested heavily in developing new generation resources across North America, and we're pleased to support Oracle as it continues to expand its operations in Texas. These agreements reflect the strength of our portfolio and our ability to deliver customized energy solutions that help customers meet their business objectives.”

Computer technology and cloud computing company Oracle is working towards its goal to match 100 percent of AI data center electricity use with carbon-free electricity by 2035.

"Oracle is taking a responsible approach to meeting the energy needs of our growing AI and cloud operations in Texas — investing in carbon-free electricity without shifting costs to consumers," Julia Robin, head of infrastructure planning and sourcing for Oracle Cloud Infrastructure, added in the release. "Our agreements with ENGIE advance Oracle's goal to match 100 percent of our AI data center electricity use with carbon-free electricity by 2035, while supporting long-term economic growth with no cost impact to the state of Texas.”

ENGIE also recently won the 2026 Green Power Leadership Award in the Market Innovation category for its work advancing 24/7 renewable energy solutions. The awards honor individuals and companies advancing sustainability and renewables in the energy industry through innovation and leadership.

The company has inked major deals to supply renewable energy to other major companies like Meta, Daikin and others.

Houston energy and innovation leaders come together at Argonne National Laboratory

The view from heti

Nearly 20 companies from Houston, ranging from global multinationals to innovative startups, joined the team at Argonne National Laboratory in Lemont, Illinois, for a full day of meetings, discussions, and networking focused on advancing innovation, commercialization, and industry collaboration.

The fly-in organized by the Houston Energy Transition Initiative, provided a unique opportunity for companies to engage directly with Argonne researchers, technical experts, and leadership while gaining a deeper understanding of the laboratory’s world-class capabilities. Participants explored how national laboratories can help bridge the gap between breakthrough research and commercial deployment, particularly in areas critical to U.S. competitiveness and economic growth.

The significance of this engagement extends beyond a single visit. While the U.S. Department of Energy operates 17 national laboratories, none is located along the Gulf Coast, a region uniquely home to industry, infrastructure, and energy systems at commercial scale. HETI’s continued work with the national laboratories helps bridge that geographic and operational gap by connecting world-class scientific research with companies that understand how to scale and deploy technologies. The Argonne fly-in also created space to address practical barriers to collaboration, including complex agreements and lengthy contracting timelines, and to explore ways to establish partnership frameworks more efficiently.

Explore HETI’s key takeaways from the fly-in:

1. Scaling Technologies for Commercial Use

A central theme was the importance of scale-up infrastructure and the role Argonne plays in helping companies reduce technical and manufacturing risks. Participants learned how facilities such as the Materials Engineering Research Facility (MERF) support the transition from laboratory discoveries to pilot-scale production and ultimately commercial manufacturing. These capabilities are especially valuable for companies working to move promising technologies from concept to market.

The discussions also highlighted Argonne’s extensive work in critical materials, battery recycling, advanced manufacturing, and supply chain resilience. Attendees learned about initiatives including the ReCell Center, AI-enabled materials discovery, and advanced modeling tools that can help businesses understand supply chain vulnerabilities and evaluate mitigation strategies. These capabilities have applications across energy, chemicals, manufacturing, semiconductors, defense, and emerging technologies.

2. Creating Pathways for Collaboration

Another key takeaway was the importance of engaging early. Companies do not need to arrive with a fully developed project or solution. Argonne offers multiple pathways for collaboration, including sponsored research, user facility access, technology licensing, pilot-scale testing, and Cooperative Research and Development Agreements (CRADAs). These partnerships help companies access specialized expertise, facilities, and analytical tools that can accelerate innovation and commercialization

3. Building Connections Across Industry and Research

The fly-in reinforced the value of relationship building. Bringing together nearly 20 organizations in one place created meaningful opportunities for collaboration, knowledge sharing, and identifying future projects.

The conversations throughout the day demonstrated a shared commitment to strengthening domestic innovation, developing resilient supply chains, and creating pathways to bring new technologies to market.

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This article originally appeared on the Greater Houston Partnership's Houston Energy Transition Initiative blog. HETI exists to support Houston's future as an energy leader. Learn more about HETI’s role in advancing solutions and building partnerships to leverage Houston’s industry leadership for an energy-abundant, low-carbon future.

Fervo produces first geothermal power at flagship Utah project

energy milestone

Fervo Energy’s flagship project in Utah just generated its first geothermal power.

The electricity is now flowing to the power grid from one of Cape Station’s three generation units, Houston-based Fervo said in a news release. This represents an early but important milestone for the project, as the unit isn’t scheduled to deliver contracted power until Oct. 1.

The achievement, coming four months after Fervo’s roughly $2.2 billion IPO, demonstrates the viability of enhanced geothermal systems (EGS).

“This is a gamechanger for the geothermal industry. It establishes EGS as the defining new power generation technology of our time, and we believe it shows that the commercial and technical maturity of EGS is ready to meet the urgent need for reliable, clean power,” Tim Latimer, co-founder and CEO of Fervo, said in the release.

The plant’s two other units are scheduled to launch commercial operations on Jan. 1.

The three units make up the project’s 99-megawatt first phase. The next phase, which will add 400 megawatts of capacity, is under construction. The second phase is set to go online in 2028.

Altogether, Cape Station will provide more than 4 gigawatts of capacity, with 900 megawatts already spoken for. The 900 megawatts of contracted electricity would be enough to power nearly 1 million U.S. homes per year.

“Cape Station works because we treated the subsurface like an engineering challenge,” Jack Norbeck, co-founder and chief technology officer of Fervo, added in the release. “Years of drilling, completion design, subsurface modeling, and flow testing led to this moment, and this is the validation that matters most.”

Enhanced geothermal continuously draws on heat that’s deep underground, producing electricity around the clock regardless of weather or time of day. That makes it one of the only carbon-free resources capable of constant power delivery, which is critical for data centers and AI infrastructure.

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