Houston startup gears up to deliver geothermal energy

ready to drill

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.

Kanin Energy set up shop in Greentown Labs last year to grow its impact on the energy transition. Photo via Getty Images

This energy transition startup taps Houston to grow, build its waste-heat-to-power tech

eyes on hou

Waste heat is everywhere, but in Houston, the Energy Capital of the World, it is becoming a hot commodity. What is it? Janice Tran, CEO of Kanin Energy, uses the example of turning ore into steel.

“There’s a lot of heat involved in that chemical process,” she says. “It’s a waste of energy.”

But Kanin Energy can do something about that. Its waste-heat-to-power, or WHP, concept uses a technology called organic rankine cycle. Tran explains that heat drives a turbine that generates electricity.

“It’s a very similar concept to a steam engine,” she says. Tran adds that the best term for what Kanin Energy does is “waste heat recovery.”

Emission-free power should be its own virtuous goal, but for companies creating waste heat, it can be an expensive endeavor both in terms of capital and human resources to work on energy transition solutions. But Kanin Energy helps companies to decarbonize with no cost to them.

“We can pay for the projects, then we pay the customers for that heat. We turn a waste product into a revenue stream for our customer,” Tran explains. Kanin Energy then sells the clean power back to the facility or to the grid, hence decarbonizing the facility gratis. Financing, construction, and operations are all part of the package.

Kanin Energy began at the height of the COVID-19 pandemic, in the spring of 2020.

“We started like a lotus. A lotus grows in mud — you start in the worst conditions and everything is better and easier from there,” says Tran.

That tough birth has helped provide the team with a discipline and thoughtfulness that’s been key to the company’s culture. Remote work has forced the team to get procedures clearly in place and react efficiently.

Back in May of 2020, its inception took place in Calgary. But the team, which also includes CDO Dan Fipke and CTO Jake Bainbridge, began to notice that many of their customers were either based in Houston or had Houston ties.

A year ago, the Kanin team visited Houston to see if the city could be a fit for an office. In July of 2022, Tran opened Kanin Energy offices in Greentown Labs.

“We’re hiring and building our team office out of Greentown. It’s been really great for us,” she says.

With the company now in its commercialization stage, Tran says that becoming part of the Houston energy ecosystem has been invaluable for Kanin.

The investments being made in climate tech and in energy transition make Space City the right place for the company. For Canadian-born Kanin Energy, Houston is now home. Investors across the nation, including Texas, are now helping Kanin to blossom, much like the lotus.

Janice Tran is the CEO and co-founder of Kanin Energy. Photo via LinkedIn

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This article originally ran on InnovationMap.

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Texas City ammonia plant acquired by Yara in $1.3 billion deal

Ammonia Acquisition

Yara North America, a subsidiary of Norwegian fertilizer and ammonia producer Yara International, has agreed to buy an ammonia production plant in Texas City for $1.3 billion.

The seller is GCA Holdings, an affiliate of Texas City-based chemical manufacturer Gulf Coast Ammonia, which is owned by private equity firms Lotus Infrastructure Partners and MB Energy.

The Texas City plant, with an eventual annual capacity of 1.3 million metric tons, is expected to start full production by the end of this year. Yara says the ammonia produced by the plant will serve its own fertilizer production system and its key customers.

During a recent call with analysts and investors, Magnus Ankarstrand, executive vice president and CFO of Yara International, said the plant holds the potential to become one of the company’s most profitable plants. The $1.3 billion purchase price, he added, “is a very attractive entry ticket to ammonia production in the U.S. at a very attractive cost.”

The Texas City plant will add to Yara’s holdings in the Lone Star State, as Yara is the majority owner of an ammonia, hydrogen and nitrogen production plant in Freeport.

Construction of the ammonia plant began in 2020, but technical and infrastructure issues delayed the project. On its website, Gulf Coast Ammonia says the plant represented a $600 million investment.

“Gulf Coast Ammonia is a world-class asset that required disciplined execution across development, financing, construction, and commercial structuring,” Philipp Pletka, managing director of Lotus Infrastructure Partners, says in a news release.

Trexlertown, Pennsylvania-based Air Products, which owns and operates the country’s largest hydrogen pipeline network, will continue to supply hydrogen and nitrogen for the plant under a long-term deal with Yara, according to the release.

However, the news comes two days after Yara International announced that it would no longer be purchasing ammonia assets in the Louisiana Clean Energy Complex (LCEC) from Air Products. In a separate release, Yara said it planned to reallocate funds toward "alternative mature U.S. ammonia investment opportunities with more competitive returns."

Houston hypersonic engine company lands $91M to accelerate production

Clean Speed

Houston-based Venus Aerospace has closed a $91 million Series B round and plans to scale the production of its hypersonic engine.

The round was led by Houston-based Mercury Fund with participation from Lockheed Martin Ventures, MESH, PEAK6, Draper Associates, Starboard Star Venture Capital, Green Sands Equity and other investors, according to a news release.

The investment comes about a year after Venus completed the first U.S. flight test of its high-thrust rotating detonation rocket engine (RDRE). The engine is expected to enable vehicles to travel four to six times the speed of sound from a conventional runway and is about 15 percent more efficient than traditional alternatives, according to the company.

Venus Aerospace says the latest round of funding will allow it to move the RDRE from demonstration to deployment and meet customer requirements for the near-term defense and space industries. The company says that the reusable RDRE is designed with a "common propulsion architecture" that can work for multiple industries and mission types.

“This financing marks an important step in moving Venus from breakthrough demonstration to scaled capability,” Sassie Duggleby, co-founder and CEO, said in the news release. “Our customers need propulsion systems that go farther, can be produced reliably and are built on supply chains they can trust. We are advancing that capability with American engineering and manufacturing talent to strengthen U.S. defense, expand space access and support the future of high-speed flight.”

Venus Aerospace raised a $20 million Series A in 2022, led by Wyoming-based Prime Movers Lab. At the time, the company said it would put the funding toward three main technologies: a next-generation rocket engine, aircraft shape and leading-edge cooling system.

The company also picked up an investment from Lockheed Martin Ventures, the investment arm of aerospace and defense contractor Lockheed Martin, in November 2025—in addition to funding from other investors over the years.

“Since our initial investment, Venus has progressed very quickly in its technology development," Chris Moran, vice president and general manager of Lockheed Martin Ventures, added in the release. "Our reinvestment in Venus recognizes Venus’ accomplishments to date and focus on speed to manufacture, cost management and reduction of supply chain constraints. Venus is working effectively to position its propulsion system for the production scale required by defense programs.”

"Venus is exactly the kind of company Houston capital should be backing," Blair Garrou, co-founder and managing partner at Mercury Fund, added in the release. "It combines multiple frontier technologies, domestic manufacturing and clear commercial and national security relevance. We believe this team is positioned to lead an important new chapter in defense and space, and we are proud to support a company building breakthrough technology here in Texas."

Venus Aerospace and Houston clean tech startup Vaulted Deep were also named to the World Economic Forum's Technology Pioneers community earlier this summer.

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This article first appeared on InnovationMap.com.

14 climatech startups join Greentown Houston in first half of 2026

green team

Climatech incubator Greentown Labs reports that 14 startups have joined its Houston community so far this year.

The companies are among 30 new startups to have joined Greentown Houston and Greentown Boston in 2026. Four of the companies are headquartered in Houston.

The startups are working on a range of "hydrogen-powered heavy-duty transport to AI-driven grid interconnection," according to Greentown.

The local startups that joined Greentown Houston include:

Houston-based Focis AI, which transforms industrial laser scans into structured asset intelligence to automatically identify, classify and map components in refineries and plants
Houston-based Iron Lattice, which develops next-generation memory technology for AI and high-performance computing that improves energy efficiency, endurance and scalability while remaining compatible with existing semiconductor manufacturing
Houston-based Orbital Arc, which is developing a new ion engine designed to improve the efficiency and scalability of spacecraft propulsion from low Earth orbit to deep space
Houston-based Sustain Energy LLC, which delivers cleaner, lower-cost fuel to industrial customers in pipeline-absent, underserved markets, cutting their energy costs and emissions with no infrastructure investment on their end

Other startups from around the world joined the Houston incubator in the same time period, including:

Ankara-based AIS Field, which develops robotic, AI-assisted non-destructive inspection systems, including submersible tank and boiler crawlers
San Francisco-based Armada AI, which builds rapidly deployable modular and edge data centers that run on local, stranded, or renewable power
San Francisco-based Armeta, which turns complex engineering drawings and legacy documentation into structured, usable data
Pittsburgh-based Atlas Robotics, which develops a Physical AI platform that powers autonomous material-handling robots and AI-guided forklifts
Ghana-based Cocoa Potash, which transforms high-emissions agricultural waste from cocoa, coconut, and palm-nut into organic potash, fertilizer and renewable energy
Israel-based Criaterra, which produces low-carbon, cement-free building materials
Italy-based ETAK, which manufactures modular reactors that convert solid waste into clean syngas
Kenya-based FelixFusion, which uses its Felix platform to model every grid connection point, including capacity, upgrade costs, and constraints
San Diego-based Gemini Energy, which builds next-generation fuel cells for data-center power
Tokyo-based Hibot, which develops robotic systems for inspecting and maintaining infrastructure in hazardous, hard-to-access environments
Austin-based Sheetak, which designs and manufactures thermoelectric coolers, generators, and assemblies for solid-state cooling and energy harvesting
The Netherlands-based ToPerform, which makes AI-powered, non-intrusive fouling sensors that monitor pipelines around the clock and predict the optimal cleaning time

Another 16 startups joined Greentown's Boston incubator. See the full list of new members here.

More than 100 startups joined Greentown last year, according to an end-of-year reflection shared by Greentown CEO Georgina Campbell Flatter. Read more about them here.

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