Houston startup Sage Geosystems released the results of its pilot at a Shell-drilled oil well in the Rio Grande Valley’s Starr County. Photo via sagegeosystems.com

As it seeks an additional $30 million in series A funding, Houston startup Sage Geosystems has released promising results from a test of its technology for underground storage of geothermal energy.

Sage says the pilot project, conducted at a Shell-drilled oil well in the Rio Grande Valley’s Starr County, showed the company’s long-term energy storage can compete on a cost basis with lithium-ion battery storage, hydropower storage, and natural gas-powered peaker plants. Peaker plants supply power during periods of peak energy demand.

Furthermore, Sage’s geothermal technology will provide more power capacity at half the cost of other advanced geothermal systems, the company says.

Sage’s storage system retrofits oil and gas wells with the company’s geothermal technology. But the company says its technology “can be deployed virtually anywhere.”

The system relies on mechanical storage instead of battery storage. In mechanical storage, heat, water, or air works in tandem with compressors, turbines, and other machinery. By contrast, battery storage depends on chemistry to get the job done.

“We have cracked the code to provide the perfect complement to renewable energy. … The opportunities for our energy storage to provide power are significant — from remote mining operations to data centers to solving energy poverty in remote locations,” former Shell executive Cindy Taff, CEO of Sage, says in a September 12 news release.

Sage says its storage capacity can be connected to existing power grids, or it can develop microgrids that harness stored energy.

An August 2023 article in The New York Times explained that Sage “is pursuing fracked wells that act as batteries. When there’s surplus electricity on the grid, water gets pumped into the well. In times of need, pressure and heat in the fractures pushes water back up, delivering energy.”

The pilot project, a joint venture between Sage and the Bureau of Economic Ecology at the University of Texas at Austin, was performed as part of a feasibility study financed by the Air Force. Now that the test results are in, Sage plans to build a prototype geothermal project at the Air Force’s Ellington Field Joint Reserve Base in Houston.

Sage says another feasibility study is underway in the Middle East in partnership with an unnamed oil and gas company.

Founded in 2020, Sage plans to raise another $30 million to accompany its previous series A funding.

The Virya climate fund and Houston-based drilling contractor Nabors Industries helped finance the pilot project in Starr County.

Last year, Sage announced it received an undisclosed amount of equity from Houston-based Ignis H2 Energy, a geothermal exploration and development company, and Dutch energy company Geolog International. Also last year, Sage said Nabors and Virya had teamed up for a $12 million investment in the startup.

Ad Placement 300x100
Ad Placement 300x600

CultureMap Emails are Awesome

8+ can't-miss events at Houston Energy and Climate Startup Week 2025

where to be

Editor's note: This article may be updated to include additional events.

The second annual Houston Energy and Climate Startup Week is less than a month away—and the calendar of events is taking shape.

The series of panels, happy hours and pitch days will take place Sept. 15-19. The Ion District will host many of the week's events.

Here are the details on some of the can't-miss events of the week:

Houston Energy & Climate Startup Week Kickoff Panel and Block Party

Join fellow innovators, founders, investors and energy leaders at this kick-off event hosted by The Ion and HETI, which will feature brief welcome remarks, a panel discussion and networking, followed by a block party on the Ion Plaza.

This event is Monday, Sept. 15, at 4 p.m. at The Ion. Register here.

Energytech Nexus Pilotathon

Grab breakfast and take in keynotes and panels by leaders from New Climate Ventures, V1 Climate, Halliburton, Energy Tech Nexus and many others. Then hear pitches during the Pilotathon, which targets startups ready to implement pilot projects within six to 12 months.

This event is Tuesday, Sept. 16, from 8 a.m.-5 p.m. at GreenStreet. Get tickets here.

Meet the Activate Houston Cohort 2025 Fellows

Meet Activate's latest cohort, which was named this summer, and also learn more about its 2024 group.

This event is Tuesday, Sept. 16, at 5 p.m. at the Ion. Register here.

New Climate Ventures Afterparty

Enjoy music, networking and carbon-negative spirits at Axelrad. Houston startups Quaise Energy, Solidec, Dimensional Energy, Rheom Materials, and Active Surfaces will also be on-site.

This event is Tuesday, Sept. 16, from 6:30-9:30 p.m. at Axelrad. Register here.

Green ICU Conference: Sustainability in Health Care for a Healthier Future

Houston Methodist will host its inaugural Green ICU Conference during Houston Energy & Climate Week. The conference is designed to bring together healthcare professionals, industry leaders, policymakers and innovators to explore solutions for building a more sustainable healthcare system.

This event is Wednesday, Sept. 17. from 8 a.m.-3 p.m. at TMC Helix Park. Register here.

Rice Alliance Energy Tech Venture Forum

Hear from clean energy startups from nine countries and 19 states at the 22nd annual Energy Tech Venture Forum. The 12 companies that were named to Class 5 of the Rice Alliance Clean Energy Accelerator will present during Demo Day to wrap up their 10-week program. Apart from pitches, this event will also host keynotes from Arjun Murti, partner of energy macro and policy at Veriten, and Susan Schofer, partner at HAX and chief science officer at SOSV. Panels will focus on corporate innovation and institutional venture capital.

This event is Thursday, Sept. 18, from 7:30 a.m.-5 p.m. at Rice University’s Jones Graduate School of Business. Register here.

Shell STCH Open House

Get a behind-the-scenes look at how Shell is leveraging open innovation to scale climate tech. The open house will spotlight two Houston-based startups—Mars Materials, which converts captured CO2 into acrylonitrile, and DexMat, which transforms methane into high-performance carbon nanotube fibers.

This event is Thursday, Sept. 18, from 8:30 a.m.-12:15 p.m. at Shell Technology Center. Register here.

ACCEL Year 3 Showcase

Celebrate Advancing Climatetech and Clean Energy Leaders Program, or ACCEL, an accelerator program for startups led by BIPOC and other underrepresented founders from Greentown Labs and Browning the Green Space. Two Houston companies and one from Austin are among the eight startups to be named to the 2025 group. Hear startup pitches from the cohort, and from Greentown's Head of Houston, Lawson Gow, CEO Georgina Campbell Flatter and others.

This event is Thursday, Sept. 18, from 5-8 p.m. at Greentown Labs. Get tickets here.

Halliburton Labs Finalists Pitch Day

Hear from Halliburton Labs' latest cohort of entrepreneurs. The incubator aims to advance the companies’ commercialization with support from Halliburton's network, facilities and financing opportunities. Its latest cohort includes one company from Texas.

This event is Friday, Sept. 19, from 8 a.m.-noon at The Ion. Register here.

Chevron Energy Innovation Finals

The University of Houston will present the 4th Annual Chevron Innovation Commercialization Competition.

The event is Friday, Sept. 19, from 10 a.m.-1:30 p.m. at the University of Houston. Register here.

Houston Energy and Climate Startup Week was founded in 2024 by Rice Alliance for Technology and Entrepreneurship, Halliburton Labs, Greentown Labs, Houston Energy Transition Initiative (HETI), Digital Wildcatters and Activate.

Last year, Houston Energy and Climate Startup Week welcomed more than 2,000 attendees, investors and industry leaders to more than 30 events. It featured more than 100 speakers and showcased more than 125 startups.





Nominations close Aug. 31 for Houston Innovation Awards — submit today

Awards Season

Calling all Houston energy innovators: The Houston Innovation Awards return this fall to celebrate the best and brightest in the Houston innovation ecosystem, and that includes those leading the energy transition.

Presented by InnovationMap, the fifth annual Houston Innovation Awards will take place November 5 at TMC Helix Park.

The awards program will honor the top startups and innovators in Houston across 10 categories, and we're asking you to nominate the most deserving Houston innovators and innovative companies, including those in the energy transition sector.

This year's categories are:

  • Minority-founded Business, honoring an innovative startup founded or co-founded by BIPOC or LGBTQ+ representation.
  • Female-founded Business, honoring an innovative startup founded or co-founded by a woman.
  • Energy Transition Business, honoring an innovative startup providing a solution within renewables, climatetech, clean energy, alternative materials, circular economy, and beyond.
  • Health Tech Business, honoring an innovative startup within the health and medical technology sectors.
  • Deep Tech Business, honoring an innovative startup providing technology solutions based on substantial scientific or engineering challenges, including those in the AI, robotics, and space sectors.
  • Startup of the Year (People's Choice), honoring a startup celebrating a recent milestone or success. The winner will be selected by the community via an interactive voting experience.
  • Scaleup of the Year, honoring an innovative later-stage startup that's recently reached a significant milestone in company growth.
  • Incubator/Accelerator of the Year, honoring a local incubator or accelerator that is championing and fueling the growth of Houston startups.
  • Mentor of the Year, presented by Houston Community College, honoring an individual who dedicates their time and expertise to guide and support budding entrepreneurs.
  • Trailblazer, honoring an innovator who's made a lasting impact on the Houston innovation community.

Nominations may be made on behalf of yourself, your organization, and other leaders and institutions in the local innovation scene. The nomination period closes on August 31, so don't delay — nominate today at this link, or fill out the embedded form below.

A panel of esteemed judges will review the nominations, and determine the finalists and winners. Finalists will be unveiled on InnovationMap.com on September 30, and the 2025 Houston Innovation Awards winners will be announced live at an event on November 5.

Tickets will go on sale this fall. Stay tuned for that announcement.

Interested in Innovation Awards sponsorship opportunities? Please contact sales@innovationmap.com.

Greentown Labs names first head of philanthropy

new hire

Greentown Labs has named its first-ever head of philanthropy in an "all hands on deck" move to advance philanthropic support for climatetech ventures.

Stacey Harris will join the clean energy incubator and brings more than 15 years of experience to the role, having led major partnerships at organizations like Make-A-Wish International, Movember, Net Impact and the Greater Phoenix Economic Council, according to a release from Greentown.

Harris will be based out of Greentown's Boston-area incubator but will support both its Texas and Massachusetts locations. Greentown maintains headquarters in Houston and Somerville, Massachusetts.

“Stacey brings national reach, local roots, and the entrepreneurial spirit we need,” Georgina Campbell Flatter, CEO of Greentown, said in the release. “She understands that philanthropy isn’t just about raising funds—it’s about building a movement, sustaining an ecosystem, and accelerating change together.”

In her new role, Harris will be tasked with designing and leading a philanthropic strategy that aligns with Greentown's corporate partnerships.

The incubator said in the release that Harris's hire is coming at a "pivotal moment," and the organization is "calling for all hands on deck" to support the clean energy space. "This includes inspiring states and local governments to lean in, individuals and family offices to step up, foundations to mobilize resources, and industry to invest boldly," the release states.

"Philanthropy has the unique power to accelerate innovation where it matters most—by backing the people and ideas that can change the world,” Harris added in the release. “At Greentown, I see an incredible opportunity to partner with local communities in Massachusetts and Texas, while also mobilizing catalytic funds that fuel entrepreneurs globally. I’m energized to work across donors, foundations, and industry to ensure these founders have what they need to go further, faster—together.”

Harris is the latest in a series of new hires for Greentown.

Lawson Gow, founder of The Cannon co-working space and former managing partner at Helium Capital, was named Greentown's Head of Houston in July. Flatter was also named as the organization's new CEO in February, after Naheed Malik was named its new CFO in January.