Criterion Energy Partners is aiming to be a next-gen energy company. Photo via Getty Images

Sean Marshall and Danny Rehg founded Criterion Energy Partners in 2020 with the hope that geothermal energy could be the cleaner, safer wave of the future. Less than three years later, the team is close to making their plan a reality thanks to a geothermal well that they hope to drill this year.

Entrepreneurship wasn’t always part of the plan for either partner. When Marshall enrolled in the MBA program at Rice University’s Jones School of Business in 2016, he had a successful career at Credit Suisse and had his eye set on a future political career. But then he met classmate Rehg, whose background was in petroleum engineering. Their wives were both attorneys in the Houston district attorney’s office and the couples became fast friends. They also realized that, as Marshall now puts it, Rehg knew how to drill wells and he knew how to make deals.

In the ensuing years, both Rehg and Marshall's careers evolved and, eventually, the pair started looking for other opportunities. That’s when they read an article in Rolling Stone about geothermal energy.

“It was really a place where it really felt like this was something we were put here to do,” says Marshall.

Marshall and Rehg spent the ensuing months “like rats in a dumpster” learning about the players and opportunities in the geothermal industry and built from there. They learned about Pleasant Bayou Power Plant, a 1989 geothermal energy project based in Brazoria County that was backed by the U.S. Department of Energy.

Last summer, Criterion Energy Partners, a member of Greentown Houston, closed on a 10,000-acre lease around the site of Pleasant Bayou.

"We hope by the end of this year we will be generating electrons,” says Marshall.

Though the company has a patented technology that connects wells to the grid, called Criterion Geothermal System, Marshall says that some of the best advice he’s gotten was, “Don’t fall in love with your technology; fall in love with the problem.” The 2021 Texas freeze reminded the founders what that was.

“People were looking for cleaner, lower-emission power sources and [there was] a need for energy resiliency,” says Marshall, explaining that the freeze created an ideal situation for the company, as people began to think more outside the grid.

The year 2022 was a big one for Criterion Energy Partners. Oil and gas powerhouse Patterson-UTI invested in the company, followed by funding from the Department of Energy. The money not only allowed Criterion Energy Partners to lease their land, they are also now paying 12 salaries, including those of the founders. The team offices in The Cannon’s Esperson coworking space.

“Our mission is to make geothermal commercially viable everywhere,” says Marshall. “I still believe in that.”

However, Criterion Energy Partners may be even bigger than proving an alternative energy source. Marshall says that geothermal is the foundation on which they are building “a next-generation energy company.” Criterion Energy Partners could be the more stable basis for a whole new energy system.

Sean Marshall and Danny Rehg founded Criterion Energy Partners in 2020. Photos courtesy

------

This article originally ran on InnovationMap.

Here's what startups took home wins at CERAWeek. Photo by Natalie Harms/InnovationMap

8 energy tech startups recognized at Houston's CERAWeek pitch competition

taking home the W

Over 200 startups participated in CERAWeek this year, and 18 of those companies pitched at a Greater Houston Partnership event.

The Houston Energy Transition Initiative, an initiative to promote Houston's work within the energy transition, hosted its second annual HETI Energy Ventures Competition at CERAWeek Innovation Agora. The competition was divided into four categories. The first batch of startups consisted of five companies from the Texas Entrepreneurship Exchange for Energy, or TEX-E, a collaboration with Greentown Labs, MIT’s Martin Trust Center for Entrepreneurship, and universities across Texas.

The winning startups shared $50,000 of prizes, sponsored by TEX-E. Houston-based Helix Earth Technologies — which has developed high-speed, high-efficiency filter systems derived from technology originating at NASA — won both the first place prize and fan favorite for the category. Helix's co-founders, Rawand Rasheed and Brad Husick from Rice University, walked away with $25,000 in prizes

Founded by Bryon Praslicka, Daniel Zamarron, and Craig Newman from Texas A&M University, Flux Works LLC, and its magnetic gear technology, took second place and $15,000 home. Tierra Climate, a two-sided marketplace for carbon offsets and other sustainability efforts founded by Emma Konet and Jacob Mansfield from Rice University, won third place and $10,000.

Helix Earth Technologies walked away with the top prize of the TEX-E category. Photo via greentownlabs.com

The next sets of startup pitches we broken down by funding stages — pre-seed and seed, series A, and series B and beyond.

Red Shift Energy, uses plasma energy to produce hydrogen from hydrogen sulfide, won fan favorite in the pre-seed and seed category sponsored by HX Venture Fund. A member of Halliburton Labs, the company also was recognized as Chevron favorite.

Per the judging panel, CanaGas won the title of most promising in the pre-seed and seed category sponsored by Alchemy Industrial. The Canadian company liquifies natural gas without costly cryogenics or stripping of the gas.

Houston-based Criterion Energy Partners won both the most-promising series A company category sponsored by SLB, but also the fan favorite series A category sponsored by Guerrella LLC. A geothermal energy tech company, Criterion was also a member of Rice's inaugural Clean Energy Accelerator cohort.

OptiSeis Solutions also won in both categories for the series B track. The company, a geophysical acquisition design and software company, won the title of most promising in the series B category sponsored by Pana LCE Investments and the series B fan favorite category sponsored by Halliburton Labs.

Lastly, the competition named the Most Impactful DEI, a category sponsored by Pana LCE Investments. Austin-based Gazelle Ecosystems, a social innovation startup with eco-solutions for corporations, won that category.

------

This article originally ran on InnovationMap.

Ad Placement 300x100
Ad Placement 300x600

CultureMap Emails are Awesome

Houston clean energy leader to receive posthumous Trailblazer Legacy Award

lasting legacy

Every year, the Houston Innovation Awards, presented by EnergyCapital's sister site InnovationMap, honor one Houstonian with the Trailblazer Award, whose impact is felt throughout the city's innovation and business ecosystem.

This year, the Trailblazer Legacy Award will be given posthumously to Don Kendall Jr., who died in September while on a trip to the Republic of the Congo with the Jane Goodall Institute, one of the many organizations he was deeply involved with.

Kendall's obituary puts it simply: "Don’s truest passions were conservation and his family." Many saw those passions play out in his career, particularly in the role he played in shaping Houston's clean energy sector.

Kendall served as general partner of New Climate Ventures, a Houston-based early-stage venture capital firm that invests in next-gen energy, materials and fuel technologies and startups. The firm's portfolio includes Houston-based clean energy companies like Solidec, Syzygy Plasmonics and Rheom Materials.

Kendall was also founding managing director and CEO of Kenmont Capital LP. He ran a $500 million distressed debt and credit-based hedge fund focused on the energy, power and transportation sectors and one of the top-performing private equity funds under the Kenmont umbrella.

He served on the board of Talos Energy, American Midstream Partners, Syzygy Plasmonics, Tangent Energy, Stream Energy and others. Notably, he served as Chair of the Special Committee of the SolarCity board during its acquisition by Tesla in 2016. According to his obituary, Kendall negotiated with "Elon Musk in the middle of the night on a rickety pier in Indonesia after eluding a poisonous snake."

Outside of the clean energy space, Kendall also served on the boards of the Jane Goodall Institute, Earthwatch International and Ecological Defense Group. He also served as vice chair of the Houston Zoo Inc. and chair of its Conservation Committee.

Kendall was selected by our esteemed panel of judges to receive the 2026 Trailblazer Legacy Award. The panel includes carbon removal entrepreneur and CEO of Houston-based Mars Materials Aaron Fitzgerald.

Fitzgerald shares the profound impact Kendall had on his career and those of many others.

"Honoring Don with the Trailblazer Legacy Award is a fitting tribute to a leader whose impact spanned civic work with the Houston Zoo, wildlife conservation, and the growth of our startup ecosystem," Fitzgerald says. "He paired a keen eye for potential with the relentless drive to unlock it. For Mars Materials, his early backing carried us through a critical valley when we needed belief the most, and his presence as a personal mentor is profoundly missed."

Don was an avid traveler, cyclist and collector. He is survived by his wife of 50 years, Diane S. Kendall. A celebration of life will be held early in 2027.

---

This article originally appeared on our sister site, InnovationMap.

Katy’s TerraFlow acquires Houston battery tech startup FlowCellutions

m&a activity

Katy-based TerraFlow Energy, an energy storage and infrastructure company, has acquired Houston-based battery technology startup FlowCellutions. Financial terms weren’t disclosed.

FlowCellutions still operates under its established name, but with the tagline “A TerraFlow Energy Company.” Becca Segel, founder and CEO of FlowCellutions, now runs the business as its president.

FlowCellutions specializes in electrochemical sensing, diagnostics, analytics, and testing that offer insights into battery chemistry, charging capabilities, and system performance.

“FlowCellutions has always been focused on developing better ways to understand what is happening inside a flow battery and using that information to improve how these systems perform,” Segal said in a press release. “Joining TerraFlow gives us the opportunity to apply that work at a much larger scale while continuing to build the capabilities and expertise that make FlowCellutions unique.”

The FlowCellutions platform supports data centers and other heavy users of power. It’s designed to help reduce operating costs, prevent failures and costly downtime, and extend battery lifetime from about seven years to more than 30 years.

Segel founded the company in 2022. A member of Greentown Labs, the company raised more than $2 million in non-dilutive funding and received $1.5 million in National Science Foundation funding earlier this year.

FlowCellutions is one of five finalists in the Energy Transition Business category of InnovationMap’s 2026 Houston Innovation Awards.

“FlowCellutions brings a depth of scientific and technical expertise that fits naturally with where TerraFlow is going,” Jon Parrella, CEO of TerraFlow, said in the release.

“As we move from developing these systems to deploying them at commercial scale, understanding performance at a deeper level matters,” he said. “Bringing FlowCellutions into TerraFlow strengthens that capability and gives both teams more opportunity to advance the technology.”

TerraFlow, founded in 2024, develops long-duration energy storage and power infrastructure for data centers, industrial facilities, utilities and other large power consumers.