Cindy Taff of Sage Geosystems shares her vision for her company and for the future of energy. Photo courtesy of Sage

When Cindy Taff was a vice president at the giant oil and gas company Shell in Houston, her middle schooler Brianna would sometimes look over her shoulder as she worked from home.

“Why are you still working in oil and gas?” her daughter asked more than once. “Is there a future in it? Why aren’t you moving into something clean?”

The words weighed on Taff.

“As a parent you want to give direction, and was I giving her the right direction?” she recalled.

At Shell, Taff was in charge of drilling wells and bringing them into production. She worked on oil and natural gas that's called unconventional in the industry, because the oil or natural gas is difficult to get out of the ground — it doesn't naturally gush out like in movies. It's a term often used for oily shale rock. Taff was somewhat unconventional for the industry, too. Her coworkers used to tease her for driving an efficient hybrid.

“You’re not helping oil and gas prices by driving a Prius," they'd say.

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EDITOR’S NOTE: This is part of an occasional series of personal stories from the energy transition — the change away from a fossil-fuel based world that largely causes climate change.

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Taff wanted Shell to pursue the energy that comes from the Earth's natural heat — geothermal. Her team looked into it, but Shell never greenlit any of those projects, saying it would take too much time to recoup the investment.

When Brianna went to college, she was passionate about energy too, but she wanted to work on renewables. After her sophomore year, in the summer of 2020, she got an internship at a geothermal company — one that in fact had just been launched by Taff's former colleagues at Shell — Sage Geosystems in Houston.

Now it was Taff looking over her daughter's shoulder and asking question as she worked from home during the pandemic.

And Sage executives were talking to Brianna, too. “We could use your mom here," they said. "Can you get her to come work for us?” Brianna recalled recently.

That's how Cindy Taff left her 36-year career at Shell to become chief operating officer at Sage.

“I didn't understand why Shell wasn't pursuing it,” she said about applying the company's drilling expertise to heat energy. "Then I got this great opportunity to pivot from oil and gas and work with these guys that I have the utmost respect for. And also, I wanted to make my daughter proud, quite frankly.”

Brianna Byrd, now 24, is the operations engineer and spokesperson at the company. She's glad her mother, now CEO, left oil and gas.

“Of course I’m biased, she’s my mom, but I don’t think Sage would be where it is without her,” she said.

The United States is a world leader in electricity made from geothermal energy, but this kind of electricity still accounts for less than half a percent of the nation’s total large-scale generation, according to the U.S. Energy Information Administration. In 2023, most geothermal electricity came from California, Nevada, Utah, Hawaii, Oregon, Idaho and New Mexico, where there are reservoirs of steam, or very hot water, close to the surface.

The Energy Department estimates this next generation of geothermal projects, like what Sage is doing, could provide some 90 gigawatts by 2050 — enough to power 65 million homes or more. That hinges on private investment, and on companies like Sage introducing this form of energy to regions where, until now, it’s been thought to be impossible.

How it works

Sage has two main technologies: The first makes electricity out of heat. The company drills wells and fractures hot, dry rock. Then electric pumps push water into those fractures, heating it up, and the hot water gets jettisoned to the surface where it spins a turbine.

But a funny thing happened during testing in Starr County, Texas. In late 2021, the team realized much of their technology could also be used to store energy.

If that works, it could be a big deal. Currently, to store energy at large scale, the United States is adding batteries, mostly lithium-ion type, to solar and wind projects, so they can charge up and send electricity back to the electric grid when the sun is not shining or the wind is not blowing. These batteries typically supply four hours maximum power.

Sage envisions some of its technology placed at solar and wind farms, too. When electricity demand is low, they'll use extra energy from a solar or wind farm to run electric pumps, pumping water into the underground fractures, leaving it there until demand for electricity increases — storing the energy beneath the Earth's surface for hours, days or even weeks.

It's a novel way to use the technology, said Silviu Livescu, lead author on a report looking at the future of geothermal in Texas. Livescu knows Taff and has followed the company's progress.

“It’s the right moment for companies like Sage with a purpose, with a mission and with the technology to show that geothermal indeed is the energy source we need to address climate change,” said Livescu, who co-founded a different geothermal startup in Austin, Texas.

These days, Taff is often out in front, talking with politicians and policymakers about the potential of geothermal. She attended the United Nations COP28 climate talks last year to share her vision for this kind of energy.

Sage has raised $30 million so far and is growing.

It's building a small (3-megawatt), geothermal energy storage system at San Miguel Electric Cooperative, Inc., south of San Antonio this year. It's working with U.S. military facilities in Texas that see geothermal as a way to power their bases securely. Sage recently announced partnerships for heating communities in Bucharest, Romania; clean electricity from geothermal for Meta's data centers, and energy storage and geothermal projects in California.

The company is final-testing a proprietary turbine to more efficiently convert heat to electricity.

Because of her oil and gas background, Taff said she knows geothermal will only be adopted widely if the cost comes down. The mantra at Sage is: It's going to be clean and it's going to be cheap. She's excited to be working in a field she feels is on the cusp of playing a big role in cleaning and stabilizing the electrical grid.

“I’ve never looked back,” she said. “I love what I’m doing and I think it’s going to be transformative.”

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Texas female-founded companies raised more than $1 billion in 2024, VC data shows

by the numbers

Female-founded companies in Dallas-Fort Worth may rack up more funding deals and more money than those in Houston. However, Bayou City beats DFW in one key category — but just barely.

Data from PitchBook shows that in the past 16 years, female-founded companies in DFW collected $2.7 billion across 488 deals. By comparison, female-founded companies in the Houston area picked up $1.9 billion in VC through 343 deals.

Yet if you do a little math, you find that Houston ekes out an edge over DFW in per-deal values. During the period covered by the PitchBook data, the value of each of the DFW deals averaged $5.53 million. But at $5,54 million, Houston was just $6,572 ahead of DFW for average deal value.

Not surprisingly, the Austin area clobbered Houston and DFW.

During the period covered by the PitchBook data, female-founded companies in the Austin area hauled in $7.5 billion across 1,114 deals. The average value of an Austin deal: more than $6.7 million.

Historically, funding for female-established companies has lagged behind funding for male-established companies. In 2024, female-founded companies accounted for about one-fourth of all VC deals in the U.S., according to PitchBook.

PitchBook noted that in 2024, female-founded companies raised $38.8 billion, up 27 percent from the previous year, but deal count dropped 13.1 percent, meaning more VC for fewer startups. In Texas, female-founded companies brought in $1.3 billion last year via 151 deals. The total raised is the same as 2023, when Texas female founders got $1.3 billion in capital across 190 deals.

“The VC industry is still trying to find solid footing after its peak in 2021. While some progress was made for female founders in 2024, particularly in exit activity, female founders and investors still face an uphill climb,” says Annemarie Donegan, senior research analyst at PitchBook.

Here are 3 Houston innovators to know right now

Innovators to Know

Editor's note: These Houston innovators are making big strides in the fields of neurotechnology, neurodevelopmental diagnosis, and even improving the way we rest and recharge.

For our latest roundup of Innovators to Know, we meet a researcher who is working with teams in Houston and abroad to develop an innovative brain implant; a professor who has created an AI approach to diagnosis; and a local entrepreneur whose brand is poised for major expansion in the coming years.

Jacob Robinson, CEO of Motif Neurotech

Houston startup Motif Neurotech has been selected by the United Kingdom's Advanced Research + Invention Agency (ARIA) to participate in its inaugural Precision Neurotechnologies program. The program aims to develop advanced brain-interfacing technologies for cognitive and psychiatric conditions. Three Rice labs will collaborate with Motif Neurotech to develop Brain Mesh, which is a distributed network of minimally invasive implants that can stimulate neural circuits and stream neural data in real time. The project has been awarded approximately $5.9 million.

Motif Neurotech was spun out of the Rice lab of Jacob Robinson, a professor of electrical and computer engineering and bioengineering and CEO of Motif Neurotech.

Robinson will lead the system and network integration and encapsulation efforts for Mesh Points implants. According to Rice, these implants, about the size of a grain of rice, will track and modulate brain states and be embedded in the skull through relatively low-risk surgery. Learn more.

Dr. Ryan S. Dhindsa, Dhindsa Lab

Dr. Ryan S. Dhindsa, assistant professor of pathology and immunology at Baylor and principal investigator at the Jan and Dan Duncan Neurological Research Institute at Texas Children’s Hospital, and his team have developed an artificial intelligence-based approach that will help doctors to identify genes tied to neurodevelopmental disorders. Their research was recently published the American Journal of Human Genetics.

Dhindsa Lab uses “human genomics, human stem cell models, and computational biology to advance precision medicine.” The diagnoses that stem from the new computational tool could include specific types of autism spectrum disorder, epilepsy and developmental delay, disorders that often don’t come with a genetic diagnosis.

“Although researchers have made major strides identifying different genes associated with neurodevelopmental disorders, many patients with these conditions still do not receive a genetic diagnosis, indicating that there are many more genes waiting to be discovered,” Dhindsa says. Learn more.

Khaliah Guillory, Founder of Nap Bar

From nap research to diversity and inclusion, this entrepreneur is making Houston workers more productiveFrom opening Nap Bar and consulting corporations on diversity and inclusion to serving the city as an LGBT adviser, Khaliah Guillory is focused on productivity. Courtesy of Khaliah Guillory

Khalia Guillory launched her white-glove, eco-friendly rest sanctuary business, Nap Bar, in Houston in 2019 to offer a unique rest experience with artificial intelligence integration for working professionals, entrepreneurs and travelers who needed a place to rest, recharge and rejuvenate.

Now she is ready to take it to the next level, with a pivot to VR and plans to expand to 30 locations in three years.

Guillory says she’s now looking to scale the business by partnering with like-minded investors with experience in the wellness space. She envisions locations at national and international airports, which she says offer ripe scenarios for patrons needing to recharge. Additionally, Guillory wants to build on her initial partnership with UT Health by going onsite to curate rest experiences for patients, caregivers, faculty, staff, nurses and doctors. Colleges also offer an opportunity for growth. Learn more.

United breaks ground on $177 million facility and opens tech center at IAH

off the ground

United Airlines announced new infrastructure investments at George Bush Intercontinental Airport as part of the company’s ongoing $3.5 billion investment into IAH.

United broke ground on a new $177 million Ground Service Equipment (GSE) Maintenance Facility this week that will open in 2027.

The 140,000-square-foot GSE facility will support over 1,800 ground service vehicles and with expansive repair space, shop space and storage capacity. The GSE facility will also be targeted for LEED Silver certification. United believes this will provide more resources to assist with charging batteries, fabricating metal and monitoring electronic controls with improved infrastructure and modern workspaces.

Additionally, the company opened its new $16 million Technical Operations Training Center.

The center will include specialized areas for United's growing fleet, and advanced simulation technology that includes scenario-based engine maintenance and inspection training. By 2032, the Training Center will accept delivery of new planes. This 91,000-square-foot facility will include sheet metal and composite training shops as well.

The Training Center will also house a $6.3 million Move Team Facility, which is designed to centralize United's Super Tug operations. United’s IAH Move Team manages over 15 Super Tugs across the airfield, which assist with moving hundreds of aircraft to support flight departures, remote parking areas, and Technical Operations Hangars.

The company says it plans to introduce more than 500 new aircraft into its fleet, and increase the total number of available seats per domestic departure by nearly 30%. United also hopes to reduce carbon emissions per seat and create more unionized jobs by 2026.

"With these new facilities, Ground Service Equipment Maintenance Facility and the Technical Operations Training Center, we are enhancing our ability to maintain a world-class fleet while empowering our employees with cutting-edge tools and training,” Phil Griffith, United's Vice President of Airport Operations, said in a news release. “This investment reflects our long-term vision for Houston as a critical hub for United's operations and our commitment to sustainability, efficiency, and growth."