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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Sage Geosystems' South Texas facility is ready to generate and supply electricity to the grid. Photo courtesy Sage Geosystems

Sage Geosystems brings South Texas geothermal plant online

powering up

Houston-based Sage Geosystems, a provider of geothermal power, has begun full operations at its South Texas facility for the San Miguel Electric Cooperative.

Sage says the plant was recently “placed in service,” according to a news release. This means it’s fully built and tested, and ready to generate and supply electricity to the grid.

Since selling its first electricity in Q2 of this year, the facility has been operating for more than four months to evaluate aspects like efficiency and water management. Sage relied on its GeoTwin modeling tool to carry out some of the testing.

The testing demonstrates Sage’s proprietary approach to geothermal power “overcomes one of the industry’s most persistent challenges, high water losses in engineered reservoirs, while delivering the consistent performance required to scale next-generation geothermal,” co-founder and CEO Cindy Taff said in the release.

Sage says the South Texas facility will serve as a model for future projects, including one in Nevada. The Nevada facility will use Sage’s proprietary technology to extract geothermal heat from hot dry rock, creating a reliable, affordable source of carbon-free power.

During the testing period, water losses amounted to less than 10 percent. This low rate indicates most water remains in the system, enabling Sage to capture more usable energy, boost power production and improve the project’s finances, the company says.

“Commercial geothermal isn’t just about creating a reservoir. It’s about creating one whose performance can be engineered, predicted, and consistent,” Lev Ring, the company’s co-founder, president and chief technology officer, said in the release.

Since being founded in 2020, Sage has raised $159 million in outside funding. This includes a more than $97 million Series B round co-led by Ormat Technologies and Carbon Direct Capital.

Two years ago, Sage announced a deal with Meta Platforms, the parent company of Facebook and Instagram, to supply up to 150 megawatts of geothermal power to Meta data centers.

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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Houston energy startup names former Cheniere execs to C-suite

new leaders

Houston-based energy infrastructure startup Joulent has brought aboard a new chief financial officer and new chief operating officer—both former executives at Houston-based Cheniere Energy.

The C-suite moves come three months after Joulent raised $1.75 billion from National Grid Ventures.

Michael Wortley joins Joulent as co-president and CFO. Wortley most recently was executive vice president and CFO at Cheniere, an LNG producer and exporter.

In conjunction with Wortley’s hiring, Brian Boland, who was Joulent’s interim CFO, has been named executive vice president, chief investment officer, and head of strategy.

Corey Grindal comes to Joulent as co-president and COO. Grindal most recently was executive vice president and COO at Cheniere.

“As Joulent evolves to meet the growing demand for power infrastructure, our expanded leadership team will help ensure we continue delivering the execution certainty our customers, partners, and investors expect,” Chris James, Joulent’s founder and CEO, said in a press release.

“Corey and Michael are accomplished operators with exceptional records of building and leading world-class energy infrastructure businesses, where they have embedded a culture defined by operational excellence and disciplined execution,” James added.

Joulet builds dedicated power-generating facilities that feed directly into data centers and other power-dependent facilities. This eliminates the need for companies to draw power from grids.

“With an initial multi-gigawatt development portfolio and strategic partnerships across the energy, infrastructure, and data center ecosystem, Joulent is helping remove power constraints to enable the next chapter of American innovation and U.S. reindustrialization,” the company says.

The $1.75 billion minority investment from National Grid Ventures complements Joulent’s existing partnerships.

Joulent, founded in 2023, emerged from stealth mode this summer. Cambridge, Massachusetts-based GE Vernova, a provider of energy equipment and services, and investment firm Engine No. 1 formed Joulent.

Joulent’s first project, the Project Kilby natural gas facility in West Texas, will be co-located with a Microsoft data center. It’ll deliver about 2.67 gigawatts of power under a 20-year deal between Microsoft and Energy Forge One, a subsidiary of Houston-based Chevron. Engine No. 1 and Chevron teamed up to build the plant.

Lithium refiner expands into Houston with new Energy Corridor office

new to hou

Battery-grade lithium carbonate manufacturer Stardust Power has expanded into Houston’s Energy Corridor, the company tells Energy Capital.

The company’s new office will serve as a project execution hub to support operations and planning for the company’s forthcoming lithium refinery in Muskogee, Oklahoma, according to a news release. The Greenwich, Connecticut-based, publicly traded company says the facility will be one of the largest lithium refining operations in the United States. The refinery is expected to have production capacity of up to 50,000 metric tons per year and seeks to address the critical shortage of U.S. lithium refining capacity.

Battery-grade lithium carbonate is commonly used in electric vehicle batteries and energy storage systems.

The company says it chose Houston as the location for its new execution hub for its rich history of expertise in engineering, a robust energy infrastructure ecosystem, and access to a leading talent pool for engineering, procurement and construction professionals. The Houston project hub will work closely with the company’s existing office in Oklahoma City.

“The Houston office strengthens our operational footprint at a critical phase of development,” Chris Celano, COO of Stardust Power, said in the release. “By building out a dedicated project management hub in one of the most experienced energy markets in the world, we are positioning the Company for execution as we advance the Muskogee refinery.”

Currently, the Houston office plans to accommodate a workforce of about 20 people with the possibility to add staff upon reaching project milestones, according to a representative from the company.

“This expansion reflects our commitment to deliver domestic, battery-grade lithium that supports U.S. energy security and industrial growth,” Celano added in the release.

In August, Stardust Power secured an offtake agreement to supply up to 20,000 metric tons of battery-grade lithium carbonate by 2030 from the Muskogee, Oklahoma, refinery to New York-based battery technology company Charge CCCV. Stardust reports that the deal adds to a separate non-binding agreement for up to 25,000 metric tons annually for 10 years with an undisclosed global trading company.

European cleantech company breaks ground on Houston manufacturing site

coming soon

Spanish renewable energy company Power Electronics broke ground on its new 53-acre Houston campus on Sept.24.

The new site is expected to create over 400 local jobs and deliver 40 gigawatts of production capacity per year. The company said in a news release that the campus is expected to be the largest manufacturing site for power conversion systems in the U.S. Power Electronics specializes in solar, energy storage, data centers and electrification technologies.

A completion date and operational start date have not yet been announced.

“For the first time in many years, the United States will be able to meet its growing need for sustainable power generation capacity and energy resilience through local manufacturing, supported by the most advanced technology in the world,” David Salvo, CEO of Power Electronics, said in the news release. “Our [40-gigawatt] Houston Campus will help shape the future of energy and AI growth globally."

Once operational, the manufacturing site will feature two buildings of approximately 150,000 square feet and 700,000 square feet. They will house production, logistics, R&D, corporate offices, training and electronic manufacturing departments.

The company says the Houston campus will be its most automated inverter production site by using advanced technologies in production to streamline day-to-day processes. Inverters convert direct current (DC) electricity that is generated by solar panels and batteries to alternating current (AC) electricity used by electrical grids.

Power Electronics' global headquarters is in Valencia, Spain, with U.S. operations in Houston, Tampa, and Gilbert, Arizona. Its North American headquarters is located at its existing North Houston office on East Airtex Drive. Community Impact News reports that the new manufacturing site is located in the Cy-Fair/Jersey Village area.

Power Electronics shared on LinkedIn that the new Houston campus represents its commitment to its American business and will allow it to serve the market with "greater scale, proximity and local expertise." It currently has more than 116 gigawatts installed in the U.S. and is working toward a global goal of 105 gigawatts of annual global production capacity.

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