Houston cleantech startup secures $134M to develop ‘superhot’ geothermal plant

deep round

A rendering of a Quaise Energy geothermal plant. Rendering via quaise.com

Houston-based Quaise Energy, a producer of utility-scale geothermal power, raised $134 million in a Series B round to advance its “superhot” geothermal power plant.

Climate-focused San Francisco-based investment firm Prelude Ventures led the round, with participation from JERA Co., Japan’s largest power generation company, and Idemitsu Kosan, one of Japan’s largest energy companies. Nearly all existing investors, including cleantech-focused investment firm Safar Partners, participated in the round.

“We have backed Quaise since the beginning because we believed accessing superhot rock would unlock geothermal energy at a scale the world has never seen,” Mark Cupta, managing director at Prelude Ventures, said in a press release.

The startup expects more equity and debt deals to close “imminently.” Quaise has raised $230 million since its founding in 2018.

Quaise says some of the fresh funding will go toward building the world’s first commercial-scale “superhot” geothermal power plant —Project Obsidian in central Oregon. In addition, Quaise is earmarking money for continued development and commercialization of its millimeter-wave drilling system toward depths exceeding 5 kilometers (about 16,400 feet).

Quaise uses a millimeter-wave drilling system developed at the Massachusetts Institute of Technology to remove rock at depths and temperatures that aren’t economically feasible with conventional drilling. With this technology, Quaise can reach rock at temperatures of around 570 degrees to 930 degrees in most places worldwide, enabling construction of geothermal systems that rival fossil fuels and nuclear energy in power density and that rival renewables in cost.

“Our ambition is to power civilization with Earth's most compelling energy source. This round takes us from field-proven technology to first commercial revenues,” Carlos Araque, co-founder, president and CEO of Quaise, added in the release.

Quaise has demonstrated the capability of its millimeter-wave drilling system at its Central Texas test site, drilling more than about 330 feet through granite in 2025—the first time the technology penetrated basement rock at full scale in the field. The company is approaching a depth of about 3,300 feet at the same site.

Construction of Project Obsidian is underway at Oregon’s Deschutes National Forest. The project, which has the potential to generate gigawatt-scale power, is slated to deliver electricity to the Pacific Northwest grid by 2030.

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ExxonMobil and Mitsubishi are still working out details of the arrangement, such as equity participation in the project and use of the low-carbon ammonia. Photo via exxonmobil.com

Mitsubishi, ExxonMobil announce low-carbon ammonia production partnership in Baytown

dream team

Spring-based ExxonMobil has teamed up with Japan’s Mitsubishi to potentially produce low-carbon ammonia and nearly carbon-free hydrogen at ExxonMobil’s facility in Baytown.

ExxonMobil and Mitsubishi are still working out details of the arrangement, such as equity participation in the project and use of the low-carbon ammonia.

“We look forward to furthering our leadership position, alongside Mitsubishi Corporation, to advance low-carbon hydrogen and ammonia globally, helping the world achieve a lower emission future,” Dan Ammann, president of ExxonMobil Low Carbon Solutions, says in a news release.

The ammonia would be shipped to Japan for power generation, process heating, and other industrial purposes. In conjunction with this project, Mitsubishi would convert part of a liquified petroleum gas (LPG) terminal into an ammonia terminal. The Japanese conglomerate plans to partner with Japanese petroleum company Idemitsu Kosan for ammonia purchases and a joint equity stake in the Baytown project.

The Baytown project is expected to generate as much as one billion cubic square feet of low-carbon hydrogen per day and more than one million tons of low-carbon ammonia per year.

A financial decision on the project is set for 2025, with the project coming online in 2029.

“We are excited to be closely collaborating with ExxonMobil to develop low-carbon hydrogen and ammonia supply chains that will bridge the United States and Japan,” says Masaru Saito, CEO of Mitsubishi’s Environmental Energy Group. “Together, we will lead this joint initiative to assist in the acceleration of the hard-to-abate sectors’ transition to clean energy.”

In total, HIF has raised $200 million this year. Photo via hifglobal.com

Japanese agency invests $36M into Houston e-fuels company's portfolio

coming in hot

Houston-based electrofuel company HIF Global has secured a $36 million investment from the Japan Organization for Metals and Energy Security, a government agency.

The investment, made through an e-fuel subsidiary of Japanese energy company Idemitsu Kosan, is earmarked for HIF’s e-fuel projects in the U.S., Australia, Chile, and Uruguay.

Earlier this year, Idemitsu led a $164 million investment round in HIF. Of that amount, Idemitsu chipped in $114 million. Other investors included Houston-based Baker Hughes along with AME, EIG, Gemstone Investments, and Porsche.

In total, HIF has raised $200 million this year.

“Japan set a priority for the commercial introduction of e-fuels into its fuel supply to support their mandate for 46 percent [greenhouse gas] emissions reduction by 2030. We have already proven e-fuels are a real solution with over 18 months of e-fuels production from our Haru Oni facility in southern Chile,” says Cesar Norton, president and CEO of HIF.

In 2023, Idemitsu agreed to buy e-methanol from HIF’s $6 billion plant in Matagorda County. HIF says the plant will be the world’s first large-scale e-fuel facility. The plant is expected to produce about 1.4 million metric tons per year of e-methanol and about 300,000 metric tons of green hydrogen per year by 2027.

HIF, founded in 2016, aims to produce 150,000 barrels per day of e-fuel and recycle 25 million metric tons per year of carbon dioxide by 2035. E-fuels, which are synthetic alternatives to fossil fuels, include e-gasoline, e-diesel, and e-sustainable aviation fuel converted from e-methanol.

Using electrolyzers powered by renewable energy, HIF begins the e-fuel process by separating hydrogen from oxygen in water. The company then couples the resulting green hydrogen with recycled carbon dioxide to create carbon-neutral e-fuels.

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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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