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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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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Sage Geosystems brings South Texas geothermal plant online

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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.

Halliburton Labs adds 3 energy, materials startups to Houston incubator

green team

Three new companies have joined Halliburton Labs, the incubator for early-stage energy and hardtech startups run by Houston energy giant Halliburton.

Halliburton Labs provides the emerging companies with mentorship, industry connections, laboratory access and other resources as they work toward commercialization. The latest companies to join the incubator focus on battery materials, resource recovery and gas separation solutions to address some of the "key bottlenecks in the energy and industrial landscape," according to a news release.

The new members include:

Electroflow, a California-based company that produces lithium iron phosphate (LFP) cathode material from lithium brines through its proprietary process. LFPs are critical components in batteries used in electric vehicles, grid storage systems and industrial electrification, according to Halliburton Labs.
Osmoses, a Cambridge, Massachusetts-based company that has developed a membrane platform to reduce the energy use, cost and emissions associated with gas separations used in natural gas, hydrogen, helium and other industrial applications
SiTration Inc., another Cambridge, Massachusetts-based company that has developed electro-extraction and filtration technologies to recover critical metals like copper directly from mining waste streams more quickly and affordably. Its process has completed successful pilot projects with Tier 1 mining companies in three continents.

"Affordable and reliable molecules are essential building blocks of the energy future. Each company brings a bold, technical solution to a complex industrial challenge. We look forward to helping them scale and deploy their technologies," Andres Cabada, Halliburton Labs managing director, added in the news release.

Halliburton Labs previously added four new members from around the world —Nandina REM, Noon Energy, Proof Energy and Tidal Metals—this spring. Alumni from the incubator include Houston-based companies like NanoTech Materials, which is developing insulation and fireproofing to reduce heat transfer in buildings and outdoor infrastructure; and SolvCor, which develops water additives to improve cooling for data centers and thermal storage.

With the addition of the three new members, the incubator currently supports nine early-stage companies.

Houston companies advance 200MW green ammonia plant in South Texas

coming soon

Two global companies with a major presence in Houston are teaming up on a green ammonia plant in Port of Victoria, Texas.

Topsoe, a Danish company with operations in Houston and Bayport, Texas, has been tapped to provide ammonia synthesis technology for the project being developed by First Ammonia, a New York-based company with offices in Houston and Denmark.

The flagship 200-megawatt plant will use renewable electricity to produce green hydrogen through electrolysis, which will then be combined with nitrogen from a nearby Air Liquide pipeline to make green ammonia, according to First Ammonia. It is expected to serve both U.S. and global markets.

According to First Ammonia, every 100,000 tons of electric ammonia produced avoids approximately 240,000 tons of CO2 emissions compared to fossil ammonia

The Topsoe technology used on site is designed to be able to increase production from 10 percent to 100 percent within 30 minutes, and decrease production at a similar rate, allowing the plant to respond to fluctuations from solar- or wind-based energy sources.

“Topsoe is the world leader in ammonia synthesis, and First Ammonia is delighted to continue our partnership with them in establishing a green ammonia industry in the US and around the world,” Joel Moser, CEO of First Ammonia, said in a news release.

Topsoe has previously signed on to supply its 100-megawatt solid oxide electrolyser (SOEC) to the First Ammonia project. However, the company announced in March that it did not extend the contract after multiple delays.

The First Ammonia project was originally expected to come online by 2027 and to produce 1.1 million tonnes of green ammonia. The project is now expected to reach financial before the end of 2026, with construction slated to begin in 2027 and commercial operations launching by 2029.

“As green ammonia projects move from ambition to execution, operational flexibility becomes increasingly important,” Yassir Ghiyati, chief commercial officer at Topsoe, added in a news release. “We’re proud to support First Ammonia with technology designed to enable efficient and reliable green ammonia production. We look forward to continuing to work with the First Ammonia team to help bring this important U.S project to life.”

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