ready to drill

Houston startup gears up to deliver geothermal energy

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

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This article originally ran on InnovationMap.

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A View From HETI

Texas improved by one spot on WalletHub's Most & Least Energy-Efficient States report for 2026. Photo courtesy of ERCOT

Despite being home to a booming energy sector, Texas ranks below average on a new list of the country’s most and least energy-efficient states.

The list, compiled by personal finance website WalletHub, puts Texas at No. 34 for energy efficiency. It ranked 27th for energy efficiency of homes and 41st for energy efficiency of cars. Texas improved by one spot on the 2026 report, after coming in at No. 35 last year and No. 36 in 2024.

California took the top spot on the list this year, beating out Vermont, which claimed the No. 1 rank in 2025. South Carolina ranked No. 48. Due to data limitations, Alaska and Hawaii were excluded from WalletHub’s analysis.

In the WalletHub study, California had the lowest residential energy consumption per capita and the third-highest efficiency for home energy. At the bottom of the list, South Carolina ranked 48th for energy efficiency of homes and 35th for energy efficiency of cars.

Here’s who joined California in the top 5:

  • No. 2 Vermont
  • No. 3 New York
  • No. 4 Washington
  • No. 5 Massachusetts

WalletHub notes the average U.S. family spends at least $2,000 per year on utilities, and the average consumer spent $2,411 on gasoline in 2024.

The U.S. Department of Energy estimates that adopting energy-efficient measures in the home could reduce a family’s utility costs by as much as 25 percent. As for gas, the agency found a more fuel-efficient vehicle could save the average driver more than $1,000 per year.

“Energy efficiency doesn’t just help save the planet — it also helps save you money by lowering the amount of electricity, gas, oil, or other types of energy you need to consume,” WalletHub analyst Chip Lupo says.

“While there are some steps you can take to become more energy-efficient on your own, living in the right area can give you a big boost,” he adds. “For example, certain states have much better public transportation systems that minimize your need to drive, at least in big cities. Some places also have better-constructed buildings that retain heat better during the winter or stay cooler during the summer.”

WalletHub compiled the listing using data from the U.S. Census Bureau, National Climatic Data Center, U.S. Energy Information Administration, and Federal Highway Administration.

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