Amperon, Hertha Metals and Vaulted Deep were named to this year's Global Cleantech 100 list. Photo via Getty Images

Three Houston-area companies—Amperon, Hertha Metals and Vaulted Deep—appear on this year’s Global Cleantech 100 list.

The unranked list, generated by market intelligence and advisory firm Cleantech Group, identifies the 100 privately held companies around the world that are most likely to make a significant impact in the cleantech market over the next five to 10 years.

For the 2026 list, Cleantech Group received more than 24,000 Global Cleantech 100 nominations from nearly 60 countries. Cleantech Group scored those companies and narrowed the contenders to 264. An expert panel reviewed those nominees, and the list was whittled down to the 100 winners.

Here’s a rundown of the three Houston-area honorees:

Amperon

Founded in 2018 by Sean Kelly and Abe Stanway, Houston-based Amperon offers an AI-enabled energy forecasting and analytics platform designed to help stabilize electric grids. Amperon received undisclosed amounts of venture capital from National Grid Partners and Tokyo Gas Co. Ltd. last year and announced a recent investment from Samsung Ventures earlier this month.

Hertha Metals

Founded in 2022 by Laureen Meroueh, Conroe-based Hertha Metals provides a single-step process for producing sustainable steel. Last year, the company emerged from stealth mode and raised more than $17 million in venture capital.

Vaulted Deep

Vaulted Deep’s technology injects excess organic waste underground to remove carbon dioxide from the atmosphere. Julia Reichelstein and Omar Abou-Sayed founded the Houston-based company in 2023. Last year, the startup raised $32.3 million in venture capital. Also in 2025, Vaulted Deep signed a 12-year deal with software giant Microsoft to remove up to 4.9 million metric tons of carbon dioxide from the environment.

Vaulted Deep also made the list last year, along with Houston-based Syzygy Plasmonics and Fervo Energy. Fervo was also named the 2025 North American Company of the Year by Cleantech Group.

Vaulted Deep, which diverts sludgy organic waste from landfills or waterways and captures and stores carbon emissions generated, is getting off the ground with $8 million from investors. Photo via Getty Images

Houston company's sustainable spinoff launches with $8M in seed funding

vaulted with capital

Houston-based Advantek Waste Management Services, which specializes in deep-injection wells that minimize the impact of land, air, and water waste, has launched a carbon removal and storage company.

The spinoff, Vaulted Deep, is getting off the ground with $8 million in seed funding.

Vaulted diverts sludgy organic waste, such as agricultural and livestock waste, before it’s dumped in a landfill or waterway or simply left on land to decompose. It then captures and stores carbon emissions generated by the organic waste.

A study published earlier this year by Louisiana State University ecologist Brian Snyder estimated that organic waste generates five gigatons of carbon dioxide per year. A gigaton equals one billion metric tons.

Vaulted is already off to an impressive start. For one thing, the startup has raised an $8 million seed round led by New York City-based carbon removal fund Lowercarbon Capital. Other investors include Advantek and San Francisco-based climatech VC fund Earthshot Ventures.

In addition, Vaulted has already nailed down purchase commitments from Frontier, a marketplace for buyers and sellers of carbon removal credits. Ryan Orbuch, a partner at Lowercarbon, is one of Frontier’s strategic advisers.

“Vaulted is literally cleaning up the planet, scaling field-proven injection terminology to safely dispose of harmful wastes like biosolids while permanently storing away millions of tons of CO2,” Orbuch says in a Vaulted news release.

While injection sequestration sites often take years to gain permits and start operating, Vaulted already boasts two permitted sites that are up and running. Vaulted offers carbon removal for $300 per ton, compared with more than $500 per ton charged by some competitors.

Advantek founder Omar Abou-Sayed is switching from CEO to chairman of Advantek, which launched in 1999, and will serve as executive chairman of Vaulted. Julia Reichelstein, a former investor at San Francisco-based climatech VC fund Piva Capital, has been tapped as CEO of Vaulted.

“Unlike many carbon removal technologies still in R&D, Vaulted’s technology and sites can safely and permanently store carbon underground, at scale, today,” says Abou-Sayed. “The early removals we will deliver are pivotal to keeping the window open to hold our planet’s warming below 1.5 degrees Celsius.”

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Houston-based ENGIE to add new wind and solar projects to Texas grid

coming soon

Houston-based ENGIE North America Inc. has expanded its partnership with Los Angeles-based Ares Infrastructure Opportunities to add 730 megawatts of renewable energy projects to the ERCOT grid.

The new projects will include one wind and two solar projects in Texas.

“The continued growth of our relationship with Ares reflects the strength of ENGIE’s portfolio of assets and our track record of delivering, operating and financing growth in the U.S. despite challenging circumstances,” Dave Carroll, CEO and Chief Renewables Officer of ENGIE North America, said in a news release. “The addition of another 730 MW of generation to our existing relationship reflects the commitment both ENGIE and Ares have to meeting growing demand for power in the U.S. and our willingness to invest in meeting those needs.”

ENGIE has more than 11 gigawatts of renewable energy projects in operation or under construction in the U.S. and Canada, and 52.7 gigawatts worldwide. The company is targeting 95 gigawatts by 2030.

ENGIE launched three new community solar farms in Illinois since December, including the 2.5-megawatt Harmony community solar farm in Lena and the Knox 2A and Knox 2B projects in Galesburg.

The company's 600-megawatt Swenson Ranch Solar project near Abilene, Texas, is expected to go online in 2027 and will provide power for Meta, the parent company of social media platform Facebook. Late last year, ENGIE also signed a nine-year renewable energy supply agreement with AstraZeneca to support the pharmaceutical company’s manufacturing operations from its 114-megawatt Tyson Nick Solar Project in Lamar County, Texas.

Houston geothermal company raises $97M Series B

fresh funding

Houston-based geothermal energy startup Sage Geosystems has closed its Series B fundraising round and plans to use the money to launch its first commercial next-generation geothermal power generation facility.

Ormat Technologies and Carbon Direct Capital co-led the $97 million round, according to a press release from Sage. Existing investors Exa, Nabors, alfa8, Arch Meredith, Abilene Partners, Cubit Capital and Ignis H2 Energy also participated, as well as new investors SiteGround Capital and The UC Berkeley Foundation’s Climate Solutions Fund.

The new geothermal power generation facility will be located at one of Ormat Technologies' existing power plants. The Nevada-based company has geothermal power projects in the U.S. and numerous other countries around the world. The facility will use Sage’s proprietary pressure geothermal technology, which extracts geothermal heat energy from hot dry rock, an abundant geothermal resource.

“Pressure geothermal is designed to be commercial, scalable and deployable almost anywhere,” Cindy Taff, CEO of Sage Geosystems, said in the news release. “This Series B allows us to prove that at commercial scale, reflecting strong conviction from partners who understand both the urgency of energy demand and the criticality of firm power.”

Sage reports that partnering with the Ormat facility will allow it to market and scale up its pressure geothermal technology at a faster rate.

“This investment builds on the strong foundation we’ve established through our commercial agreement and reinforces Ormat’s commitment to accelerating geothermal development,” Doron Blachar, CEO of Ormat Technologies, added in the release. “Sage’s technical expertise and innovative approach are well aligned with Ormat’s strategy to move faster from concept to commercialization. We’re pleased to take this natural next step in a partnership we believe strongly in.”

In 2024, Sage agreed to deliver up to 150 megawatts of new geothermal baseload power to Meta, the parent company of Facebook. At the time, the companies reported that the project's first phase would aim to be operating in 2027.

The company also raised a $17 million Series A, led by Chesapeake Energy Corp., in 2024.

Houston expert discusses the clean energy founder's paradox

Guest Column

Everyone tells you to move fast and break things. In clean energy, moving fast without structural integrity means breaking the only planet we’ve got. This is the founder's paradox: you are building a company in an industry where the stakes are existential, the timelines are glacial, and the capital requires patience.

The myth of the lone genius in a garage doesn’t really apply here. Clean energy startups aren’t just fighting competitors. They are fighting physics, policy, and decades of existing infrastructure. This isn’t an app. You’re building something physical that has to work in the real world. It has to be cheaper, more reliable, and clearly better than fossil fuels. Being “green” alone isn’t enough. Scale is what matters.

Your biggest risks aren’t competitors. They’re interconnection delays, permitting timelines, supply chain fragility, and whether your first customer is willing to underwrite something that hasn’t been done before.

That reality creates a brutal filter. Successful founders in this space need deep technical knowledge and the ability to execute. You need to understand engineering, navigate regulation, and think in terms of markets and risk. You’re not just selling a product. You’re selling a future where your solution becomes the obvious choice. That means connecting short-term financial returns with long-term system change.

The capital is there, but it’s smarter and more demanding. Investors today have PhDs in electrochemistry and grid dynamics. They’ve been burned by promises of miracle materials that never left the lab. They don't fund visions; they fund pathways to impact that can scale and make financial sense. Your roadmap must show not just a brilliant invention, but a clear, believable plan to drive costs down over time.

Capital in this sector isn’t impressed by ambition alone. It wants evidence that risk is being retired in the right order — even if that means slower growth early.

Here’s the upside. The difficulty of clean energy is also its strength. If you succeed, your advantage isn’t just in software or branding. It’s in hardware, supply chains, approvals, and years of hard work that others can’t easily copy. Your real competitors aren’t other startups. They’re inertia and the existing system. Winning here isn’t zero-sum. When one solution scales, it helps the entire market grow.

So, to the founder in the lab, or running field tests at a remote site: your pace will feel slow. The validation cycles are long. But you are building in the physical world. When you succeed, you don’t have an exit. You have a foundation. You don't just have customers; you have converts. And the product you ship doesn't just generate revenue; it creates a legacy.

If your timelines feel uncomfortable compared to software, that’s because you’re operating inside a system designed to resist change. And let’s not forget you are building actual physical products that interact with a complex world. Times are tough. Don’t give up. We need you.

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Nada Ahmed is the founding partner at Houston-based Energy Tech Nexus.