Houston geothermal startup bumps Series B to $180M with Nabors investment

fresh funding

Quaise Energy received a boost to its Series B round. Photo courtesy Quaise

Houston-based geothermal startup Quaise Energy has closed its Series B fundraising round at $180 million after inking a significant investment from another local energy leader.

Quaise, which is developing a 50-megawatt superhot geothermal plant in Oregon, announced a "first close" of the round last month at $134 million, led by San Francisco-based investment firm Prelude Ventures. The $46 million bump has been fueled by a $35 million investment from Houston-based Nabors Industries.

The funding will go toward the continued development of the company's superhot geothermal plant, Project Obsidian, as well as the commercialization of Quaise's millimeter-wave drilling system, according to a news release.

“We are unlocking the most powerful clean energy source on Earth, and the Series B signals deep conviction across a wide range of investors,” Carlos Araque, Quaise CEO and president, said in the release. “Nabors is an invaluable partner as we move millimeter wave drilling to full commercial operations at Project Obsidian and beyond.”

Nabors, a repeat investor in Quaise, has also entered into a strategic framework agreement with Quaise. Under the agreement, Quaise will have access to a dedicated Nabors land rig and drilling platform. Nabors will also provide expertise in reservoir modeling, well design and drilling strategy.

Last year, Quaise drilled to a depth of about 330 feet using its millimeter-wave technology at its field site in Central Texas. Canary Media previously reported that Quaise plans to drill to nearly 3,300 feet later this year and to deploy its millimeter-wave technology at its power plant in 2027. The plant is expected to deliver power to the Pacific Northwest in 2030.

Quaise and Nabors say the partnership will improve drilling performance, reduce costs and accelerate project timelines.

“Superhot geothermal has the potential to make clean energy ubiquitous. That is why we are excited about our close relationship with Quaise,” Anthony Petrello, president and CEO of Nabors, added in the release. “Quaise’s millimeter wave technology changes the equation entirely by reaching superhot rock at temperatures and depths that are inaccessible with conventional drilling, transforming geothermal from a location-dependent resource into a global energy solution. Combined with Nabors’ drilling expertise and infrastructure, we see a path to gigawatt-scale geothermal power that no other company can offer today.”

Quaise reports that with the latest funding, it has now raised $280 million. It raised $21 million in a Series A1 financing round in 2024 and a $52 million Series A in 2022.

The company announced in March that it was aiming to raise $200 million for Project Obsidian through $100 million in Series B funding, plus an additional $100 million from grants, debt and project-level finance.

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

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

deep round

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.

Quaise Energy is developing Project Obsidian, a superhot geothermal plant in central Oregon. Rendering via quaise.com.

Houston cleantech startup seeks $200M for superhot geothermal plant

seeing green

Houston-based Quaise Energy is looking to raise $200 million to support the development of a 50-megawatt superhot geothermal plant in Oregon.

The company is seeking $100 million in Series B funding, plus an additional $100 million from grants, debt and project-level finance, a representative from the company tells Energy Capital. Axios first reported the news late last month.

Quaise specializes in terawatt-scale geothermal power. It is known for its millimeter-wave drilling technology, which was developed at MIT.

The company's Project Obsidian development in central Oregon will combine conventional drilling with its millimeter-wave technology. Quaise says the project, targeted to come online in 2030, could be the first commercial plant to operate in superhot rock, a more efficient and abundant resource, but one that requires more advanced and durable drilling technology.

Quaise says Obsidian would initially generate 50 megawatts of "always-on" power and would be designed to add 200 megawatts as additional wells are developed. A power-purchase deal has already been signed for the initial 50 megawatts with an undisclosed customer.

A representative from the company says Quaise would also use the funding to continue advancing its millimeter-wave technology and prepare it for commercialization.

Last year, the company drilled to a depth of about 330 feet using its millimeter-wave technology at its field site in Central Texas.

“Our progress this year has exceeded all expectations,” Carlos Araque, CEO and president of Quaise Energy, said at the time. “We’re drilling faster and deeper at this point than anyone believed possible, proving that millimeter-wave technology is the only tool capable of reaching the superhot rock needed for next-generation geothermal power. We are opening up a path to a new energy frontier.”

Canary Media reports that Quaise plans to drill to nearly 3,300 feet later this year and to deploy its millimeter-wave technology at its power plant in 2027.

Quaise raised $21 million in a Series A1 financing round in 2024 and a $52 million Series A in 2022. Major investors include Prelude Ventures, Safar Partners, Mitsubishi Corporation, Nabors Industries, TechEnergy and others.

Quaise was one of eight Houston-area companies to appear on Time magazine and Statista’s list of America’s Top GreenTech Companies of 2025.

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10 can't-miss events at Houston Energy and Climate Week 2026

where to be

Editor's note: Houston Energy and Climate Week returns for its third year, Sept. 12–18, with panels, happy hours, pitch days and tours focused on the energy transition.

The Ion District will host many of the week's events. Here are details on some can't-miss, signature events and how to register. Find the full schedule here. Please note: this article may be updated to add more events.

Sept. 13 — The & Awards

Kick off the week by celebrating Houston honorees leading the future of energy at the & Awards. The & Awards will honor Zay Zeidman, chairman of Houston First and managing partner of Altitude Ventures; The University of Houston's Renu Khator and Ramanan Krishnamoorti; Maryanne Maldonado, CEO of the World Affairs Council; and Fervo Energy co-founders Tim Latimer (CEO) and Jack Norbeck (CTO). The inaugural posthumous Lifetime Ambassador Award will honor former Houston Mayor Sylvester Turner, and this year’s Allies in Energy grant recipients will also be recognized. The evening will include a fireside chat, an immersive gallery, live music, passed hors d'oeuvres, Champagne and plenty of networking opportunities.

This event is Sunday, Sept. 13, from 6-9 p.m. at ARTECHOUSE Houston. Register here.

Sept. 14 — Brews on the Bayou

Head to Saint Arnold Brewery for a more laid-back kickoff event. Grab a beer and take in a live conversation with Paul Hobby, managing director of Genesis Park, and Katie Mehnert, CEO of The Bee Suite and co-founder of HECW. Rice University's Aaron Pomerantz will moderate the discussion. Then hear a live performance from AY Young.

This event is Monday, Sept. 14, from 6-9 p.m. at Saint Arnold Brewery. Register here.

Sept. 14–18 — Sip For Sustainability

Enjoy a signature cocktail at five H Town Restaurant Group spots each night of Houston Energy and Climate Week. A portion of every purchase will go toward Allies in Energy, which supports education, collaboration, and community programs that drive a more sustainable future. Participating eateries include Hugo's, Xochi, Uber, Zaranda and Caracol.

These events begin Monday, Sept. 14, from 3-5 p.m. Find more information on each day's happy hour here.

Sept. 15 — HTX Tech Tours

HECW will present two Tech Tours this year, offering attendees a closer look at the region's climatech scene. The Metro Innovation Tour & Market will visit Sugar Land Town Square, Shell Technology Center Houston, SLB West Houston Campus, University of Houston at Sugar Land, Ambrosia Space, NanoTech Materials and Syzygy Plasmonics. The Bay City South Innovation Tour will visit Sugar Land Town Square and Erthos Project Bravo in Matagorda County. Both tours will head to Astros Night at Daikin Park to wrap up the day.

These events are Tuesday, Sept. 15. Find more information here.

Sept. 15 — Meet the Activate Houston Cohort 2026 Fellows

Meet Activate's latest cohort, which was named this summer, and learn more about their hardtech and climate-focused solutions. Also meet founders from the organization’s 2025 cohort during Houston Energy and Climate Startup Week.

This event is Tuesday, Sept. 15, from 5-7 p.m. at the Ion. Register here.

Sept. 15 – Cypher Pilotathon and Startup Showcase

Grab coffee and take in keynotes and panels featuring leaders from Amperon, Aramco Ventures, New Climate Ventures, Syzygy Plasmonics and many others during this signature event, this year under the theme “The NEW Energy Industrial Revolution.” After lunch, hear pitches from 31 ventures during the Pilotathon. This year's event will also feature a startup showcase with interactive booths where attendees can meet founders and see demonstrations, plus an industry hub where corporates and investors can engage with emerging technologies and identify the pilots they want to move forward with.

This event is Tuesday, Sept. 15, from 9 a.m.-5 p.m. at POST Houston. Get tickets here.

Sept. 15 — Houston Astros Energy Night

Catch a game and chat with fellow clean energy enthusiasts during Houston Astros Energy Night. The 'Stros take on the Kansas City Royals. A bonus? Dollar Hot Dog Night at Daikin Park.

This event is Tuesday, Sept. 15, starting at 7:10 p.m. at Daikin Park. Get tickets here.

Sept. 16 — Greentown Labs Climatech Summit

Entrepreneurs, investors, corporate leaders, policymakers and philanthropists will head to Houston this month for the annual Greentown Climatetech Summit. Hear from Greentown CEO Georgina Campbell Flatter and keynote speaker Tim Latimer, CEO and co-founder of Houston geothermal unicorn Fervo Energy, plus numerous other engaging panels at the Ion. Then head to Greentown Labs for an open house and startup showcase, where attendees can meet some of the climatech incubators' members, before taking in the startup pitch competition followed by happy hour over at the Continental Club.

This event is Wednesday, Sept. 16, from 8 a.m.–9 p.m. at multiple locations. Register here.

Sept. 17 — Rice Alliance Energy Tech Venture Forum

Hear from clean energy startups from around the world at the 23rd annual Energy Tech Venture Forum. In addition to the pitches, this event will also host keynotes from Sean Maher, chief economist at Phillips 66, and Ira Ehrenpreis, founder and managing partner of DBL Partner. Panels will focus on technologies, infrastructure and commercialization strategies needed to deploy breakthrough innovations at scale. Following the event, the Rice Alliance will also name its annual “Most Promising” startup.

This event is Thursday, Sept. 17, from 7:30 a.m.-5 p.m. at Rice University’s Jones Graduate School of Business. Register here.

Sept. 18 — Halliburton Labs Finalists Pitch Day

Hear from Halliburton Labs' latest cohort of entrepreneurs. The incubator aims to advance the companies’ commercialization with support from Halliburton's network, facilities and financing opportunities. Its latest cohort includes one company from Texas.

This event is Friday, Sept. 18, from 8 a.m.-noon at The Ion. Register here.

UH report says CO2 technology could unlock 137B barrels of U.S. oil

oil recovery

A new report from the University of Houston estimates that a method known as carbon dioxide-enhanced oil recovery (CO2-EOR) could recover roughly 137 billion barrels of U.S. oil—with Texas and the Gulf Coast poised to play a major role.

A UH Energy-produced white paper, titled “Revitalization of Mature Oil Fields: Opportunities and Challenges of CO2-EOR,” looks at how CO2-EOR could increase U.S. energy supply, reduce carbon emissions and lower the carbon intensity of oil production.

CO2-EOR injects pressurized carbon dioxide into mature oil wells to loosen and push oil trapped underground toward the production wells, allowing operators to extract oil typically left behind. The process permanently stores some CO2 underground, reducing carbon emissions and carbon intensity.

“Injected CO2 works to revitalize mature oil fields by reducing oil viscosity, improving sweep efficiency and restoring reservoir pressure, resulting in incremental oil production beyond primary and secondary recovery,” the report reads. “CO2-EOR also supports permanent carbon storage and by virtue of this will produce uniquely low-carbon intensity oil for global markets.”

Authored by Charles McConnell, executive director of UH's Center for Carbon Management in Energy, and Zhiyuan Li, a UH petroleum engineering doctoral candidate, the paper says that much of the opportunity lies right under the feet of Texas oil companies.

Texas and the Gulf Coast, including its offshore resources, have half of the nation's oil resources considered favorable for the CO2-EOR technology, the report says. According to UH, conventional U.S. oil reservoirs contain 624 billion barrels, with 434 billion barrels still underground, including about 20 billion barrels of proven reserves.

Still, the paper argues that the economics behind CO2-EOR need to be considered. The process’ success depends on a number of factors, including costs of carbon capture, field redevelopment, operations, monitoring, transportation and available tax incentives, according to UH.

Logistically, developing CO2-EOR operations out of older wells and infrastructure presents pros and cons. While using older wells can be more economical, aging infrastructure may require more frequent monitoring, inspection, repair or re-plugging, according to UH.

Ultimately, the report recommends focusing CO2-EOR development on mature oil fields with existing infrastructure, well-understood geology and reliable CO2 supplies. This approach, UH says, could help extend the productive life of existing oil fields while supporting “lower carbon intensity oil for global markets and a significant contribution to energy security.”

Read the full report here.

Amazon's EV robotaxi service Zook is set to arrive in Houston

EV News

Amazon-owned electric robotaxi ride-hailing service Zoox is zooming into Houston in September.

Initially, self-driving retrofitted SUVs with safety drivers on board will serve downtown Houston, centrally located tourist hotspots, and certain residential neighborhoods. The SUVs will test Houston roads before Zoox rolls out autonomous robotaxis, the company says.

Zoox takes Houston for a test drive

At the outset, Zoox says, a limited number of vehicles will be driven by people to gather data about Houston roads.

“This helps create a detailed picture of each street, from road geometry to traffic lights,” the company says. “Once we have mapped out an area, we will test autonomous driving capabilities. Safety and operational readiness govern the pace of our rollout.”

Zoox says its robotaxi differs from vehicles operated by other ride-hailing services.

The all-electric robotaxi “is purpose-built for autonomous ride-hailing and designed for riders from day one,” the company says. “It has no traditional driving controls and instead has carriage-style seating, sliding glass doors, and features that let the rider personalize their journey.”

To help manage the fleet, Zoox plans to open a depot in Houston for vehicle charging and maintenance, a representative says via email.

Along with Houston, Zoox is launching this month in San Diego. The ride-hailing service already operates in Austin, Dallas, Atlanta, Las Vegas, Los Angeles, Miami, Phoenix, the San Francisco Bay Area, Seattle, and Washington, D.C.

Zoox breaks into “sprawling” Houston market

Zoox describes Houston as its “most sprawling market to date.”

“Driving here means navigating complex service-road networks, unique merging scenarios, and challenging environmental conditions, including severe heat, heavy rain, and urban flooding,” the company says. “It’s a rigorous test of our technology across geography and terrain.”

Zoox will join two other autonomous ride-hailing services in Houston:

Waymo began rolling in Houston in February. Alphabet, the parent company of Google, owns Waymo.
Electric vehicle manufacturer Tesla began offering robotaxi services earlier this year.

A third Zoox competitor is arriving within the next year. A partnership comprising rideshare provider Uber, EV manufacturer Lucid, and autonomous technology company Nuro plans to launch a robotaxi service in Houston by mid-2027.

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This article originally appeared on CultureMap.com.

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