Fervo Energy's recent IPO is a signal of where Houston's venture ecosystem stands—and where it can go. Photo via Pexels

Fervo Energy went public earlier this summer. The Houston geothermal company priced its IPO at $27 per share, raised $1.89 billion, and opened the next morning at a market capitalization north of $10 billion. By most measures, it is the largest venture-backed cleantech IPO in history and an unambiguous win for Houston. It’s also a useful moment to look at where Houston's venture ecosystem stands and where it can go. The highlight: Houston's venture ecosystem has real foundations and, with increased company formation activity, can grow into the scale our city's ambitions deserve.

A Houston energy story in the national recovery

The recent uptick in Houston venture activity follows national trends. U.S. venture deal count contracted roughly 22 percent from its 2021 peak through 2024 before rebounding to about 16,700 rounds in 2025. Houston's 23 percent increase in VC funding from 2023 to 2024 is part of a national recovery of comparable magnitude over the same time window.

The energy sector is where Houston exhibits unique trends—and where the story turns clearly positive. (Houston's strong health and space sectors deserve their own separate consideration.) By deal count, energy-related rounds have accounted for 15 to 20 percent of Houston activity, roughly consistent over the past few years.

By capital, energy's share surged from about 14 percent in 2023 to over 60 percent in 2025, driven by a small number of large Houston-headquartered rounds, primarily in geothermal and related technologies. Fervo is the obvious anchor, but Sage Geosystems, Quaise Energy, Zeta Energy, Vaulted Deep, Applied Carbon and Mariana Minerals have all closed meaningful rounds. Houston is concentrated and accelerating as an energy capital market, an invaluable position to build upon.

From foundation to scale

The institutional pieces are in place. Greentown Labs, Activate, the Ion and others have built sector-specialized infrastructure most cities would struggle to assemble. Fervo itself is an alum of both Activate and Greentown Labs. Mercury Fund closed its $160 million Fund V, its largest ever. Houston Angel Network, GOOSE Capital, Fathom Fund, and broader pre-seed and seed capital coverage are here. The Houston $10 million-plus Series A list now includes 40 rounds since 2021, which break roughly into two eras. While 2021 to 2022 was biotech-heavy, with companies like Sporos Bioventures, RadioMedix, Cellenkos and Coya Therapeutics, 2024 to 2025 has tilted clearly toward energy, climate, and critical minerals, with Vaulted Deep, Applied Carbon, Mariana Minerals, Sage Geosystems and Ignis H2 Energy among them.

What’s less developed is the volume of seed-stage companies flowing into that capital. Imagine a dozen more Fervos coming out of that infrastructure over the next decade, each generating jobs, recycled founder capital, and the next wave of operators and angel investors. That is the kind of opportunity Houston has within reach if we build the company-formation pipeline to feed it. To be relevant on the national stage as a venture market, and to drive an economy the size of Houston's into the 2030s, the city needs to be doing closer to 20 Series A rounds per month rather than per year. That throughput implies roughly 1,000 seed rounds per year, feeding the funnel at a 20 percent to 30 percent graduation rate. Reaching such throughput depends on how many new founders Houston produces and how quickly our innovation ecosystem can help them achieve lift-off.

Houston in context

The comparative picture brings the scaling challenge into focus. Between 2021 and 2024, Houston-area startups closed between 126 and 153 disclosed venture rounds per year, against a national count between 9,854 and 14,125. That places Houston at a little over 1 percent of the U.S. deal count. For comparison, Austin ran about three times Houston's deal count each year.

At the Series A level, Houston closed between 12 and 24 rounds in any given year. The median Houston Series A across the period was about $10.7 million, compared with $15.4 million in San Francisco. Houston founders are raising fewer and smaller Series A rounds than founders in peer metros, which points directly to where Houston has the most room to grow.

The unicorn picture tells the same story. From 2021 through 2025, the U.S. produced 590 venture-backed unicorns. Four were Houston-based: Solugen and Axiom Space in 2021, Cart.com in 2023, and Fervo Energy in 2024. Adding HighRadius from 2020 brings Houston's all-time total to five. Austin added 19 over the same five-year window. The path from here is to make Houston's entries on lists like these less the exception and more the rule.

Where this leads

Houston has a real opportunity to become the deepest, most credible energy and climate capital market in the country, with the company formation, talent and operator density to support it. The data shows the foundation is already in place. Fervo, Solugen and the growing roster of energy-adjacent Series A graduates are proof. Fervo's IPO is the first of what should be many. Houston has not had a venture-backed cleantech liquidity event of this scale before, and the city now has one to reference, recruit against and build on. With increased company formation at the seed and pre-seed stages, a Fervo-scale outcome need not be a generational event in Houston, but instead, it can become part of a chain reaction powering the city's economy.

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Stephanie T. Schmidt, PhD, is the founder of a stealth startup, a Venture Fellow at Energy Transition Ventures, and an Executive MBA candidate at Rice University's Jones Graduate School of Business. Lawson Gow is the Chief Operating Officer of Greentown Labs. The full Houston VC landscape report is available at Energy Transition Ventures and CleanTech.Org.

Sources: Crunchbase, PitchBook-NVCA, Carta

This guest column originally appeared on our sister site, InnovationMap.com.

Fleetzero has raised $43 million to expand the manufacturing of its hybrid and electric marine propulsion system. Photo courtesy Fleetzero.

Houston maritime startup raises $43M to electrify cargo vessels

A Houston-based maritime technology company that is working to reduce emissions in the cargo and shipping industry has raised VC funding and opened a new Houston headquarters.

Fleetzero announced that it closed a $43 million Series A financing round this month led by Obvious Ventures with participation from Maersk Growth, Breakthrough Energy Ventures, 8090 Industries, Y Combinator, Shorewind, Benson Capital and others. The funding will go toward expanding manufacturing of its Leviathan hybrid and electric marine propulsion system, according to a news release.

The technology is optimized for high-energy and zero-emission operation of large vessels. It uses EV technology but is built for maritime environments and can be used on new or existing ships with hybrid or all-electric functions, according to Fleetzero's website. The propulsion system was retrofitted and tested on Fleetzero’s test ship, the Pacific Joule, and has been deployed globally on commercial vessels.

Fleetzero is also developing unmanned cargo vessel technology.

"Fleetzero is making robotic ships a reality today. The team is moving us from dirty, dangerous, and expensive to clean, safe, and cost-effective. It's like watching the future today," Andrew Beebe, managing director at Obvious Ventures, said in the news release. "We backed the team because they are mariners and engineers, know the industry deeply, and are scaling with real ships and customers, not just renderings."

Fleetzero also announced that it has opened a new manufacturing and research and development facility, which will serve as the company's new headquarters. The facility features a marine robotics and autonomy lab, a marine propulsion R&D center and a production line with a capacity of 300 megawatt-hours per year. The company reports that it plans to increase production to three gigawatt-hours per year over the next five years.

"Houston has the people who know how to build and operate big hardware–ships, rigs, refineries and power systems," Mike Carter, co-founder and COO of Fleetzero, added in the release. "We're pairing that industrial DNA with modern batteries, autonomy, and software to bring back shipbuilding to the U.S."

Houston-based Citroniq Chemicals has secured its series A funding. Photo via Getty Images

Houston energy company backs decarbonization startup's $12M series A

money moves

A fresh $12 million round of funding will enable Houston-based Citroniq Chemicals to propel planning, design, and construction of its first decarbonization plant.

An unidentified multinational energy technology company led the series A round, with participation from Houston-based Lummus Technology Ventures and cooperation from the State of Nebraska. The Citroniq plant, which will produce green polypropylene, will be located in Nebraska.

“Lummus’ latest investment in Citroniq builds on this progress and strengthens our partnership, working together to lower carbon emissions in the plastics industry,” Leon de Bruyn, president and CEO of Lummus Technology, says in a news release.

Citroniq is putting together a decarbonization platform designed to annually capture 2 million metric tons of greenhouse gas emissions at each plant. The company plans to invest more than $5 billion into its green polypropylene plants. Polypropylene is a thermoplastic resin commonly used for injection molding.

The series A round “is just the first step in our journey towards building multiple biomanufacturing hubs, boosting the Nebraska bioeconomy by converting local ethanol into valuable bioplastics,” says Kelly Knopp, co-founder and CEO of Citroniq.

Citroniq’s platform for the chemical and plastics industries uses technology and U.S.-produced ethanol to enable low-cost carbon capture. Citroniq’s process permanently sequesters carbon into a useful plastic pellet.

Lummus Technology licenses process technologies for clean fuels, renewables, petrochemicals, polymers, gas processing and supply lifecycle services, catalysts, proprietary equipment, and digital transformation.

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This article originally ran on InnovationMap.

Branch Energy aims to provide customers with clean energy at a lower cost than competitors. Photo via Getty Images

Houston clean energy provider raises $10.8M series A

money moves

A tech-driven retail energy provider based in Houston has secured an oversubscribed series A round of funding.

Branch Energy raised a $10.8 million round led by climate-focused venture capital firm Prelude Ventures with co-investor Zero Infinity Partners, an infrastructure tech-focused firm. The fresh funding will go toward accelerating the company's battery management tech and build out the infrastructure of its field services.

A vertically integrated power provider, Branch Energy aims to provide customers with demand management software and battery storage systems to ensure long-term, stable, and clean energy at a lower cost than competitors.

“Our century-old grid design is not equipped for the complexity of today’s energy needs," Alex Ince-Cushman, Branch Energy co-founder and CEO, says in a news release. “Optimizing distributed energy assets in real-time will play an increasingly important role in managing the grid. We built Branch from the ground up as a technology company, allowing us to deliver value to customers in this new era of distributed energy by reducing costs while improving reliability."

The company chose Texas as its inaugural market based on the stress of the grid in the state, the company says in the release. Since 2021 when Branch Energy launched, it has signed up thousands of customers for its 100 percent clean energy service. The business proposition includes lowering customer's energy bills by 5 to 10 percent.

“The power grid, especially in Texas, requires distributed generation and flexible loads as basic economics drives deployment of more renewable resources,” Tim Woodward, managing partner at Prelude Ventures, adds. “Across the country, we are experiencing a major shift toward a decentralized and decarbonized grid. Branch Energy is bringing value to its customers through deployment of intelligent storage that lowers costs and improves reliability.”

Branch Energy, which is available now in some Texas regions, had previously raised $5.5 million in seed and pre-seed funding, per Crunchbase.

The series A funding will support the deployment of its biochar machines across Texas, Oklahoma, Arkansas, and Louisiana. Photo courtesy of Applied Carbon

Houston agriculture robotics co. raises $21.5M series A to grow climatetech solution

freshly funded

A Houston energy tech startup has raised a $21.5 million series a round of funding to support the advancement of its automated technology that converts field wastes into stable carbon.

Applied Carbon, previously known as Climate Robotics, announced that its fresh round of funding was led by TO VC, with participation from Congruent Ventures, Grantham Foundation, Microsoft Climate Innovation Fund, S2G Ventures, Overture.vc, Wireframe Ventures, Autodesk Foundation, Anglo American, Susquehanna Foundation, US Endowment for Forestry and Communities, TELUS Pollinator Fund for Good, and Elemental Excelerator.

The series A funding will support the deployment of its biochar machines across Texas, Oklahoma, Arkansas, and Louisiana.

"Multiple independent studies indicate that converting crop waste into biochar has the potential to remove gigatons of CO2 from the atmosphere each year, while creating trillions of dollars in value for the world's farmers," Jason Aramburu, co-founder and CEO of Applied Carbon, says in a news release. "However, there is no commercially available technology to convert these wastes at low cost.

"Applied Carbon's patented in-field biochar production system is the first solution that can convert crop waste into biochar at a scale and a cost that makes sense for broad acre farming," he continues.

Applied Carbon rebranded in June shortly after being named a top 20 finalist in XPRIZE's four-year, $100 million global Carbon Removal Competition. The company also was named a semi-finalist and awarded $50,000 from the Department of Energy's Carbon Dioxide Removal Purchase Pilot Prize program in May.

"Up to one-third of excess CO2 that has accumulated in the atmosphere since the start of human civilization has come from humans disturbing soil through agriculture," Joshua Phitoussi, co-founder and managing partner at TO VC, adds. "To reach our net-zero objectives, we need to put that carbon back where it belongs.

"Biochar is unique in its potential to do so at a permanence and price point that are conducive to mass-scale adoption of carbon dioxide removal solutions, while also leaving farmers and consumers better off thanks to better soil health and nutrition," he continues. "Thanks to its technology and business model, Applied Carbon is the only company that turns that potential into reality."

The company's robotic technology works in field, picking up agricultural crop residue following harvesting and converts it into biochar in a single pass. The benefits included increasing soil health, improving agronomic productivity, and reducing lime and fertilizer requirements, while also providing a carbon removal and storage solution.

"We've been looking at the biochar sector for over a decade and Applied Carbon's in-field proposition is incredibly compelling," adds Joshua Posamentier, co-founder and managing partner of Congruent Ventures. "The two most exciting things about this approach are that it profitably swings the agricultural sector from carbon positive to carbon negative and that it can get to world-scale impact, on a meaningful timeline, while saving farmers money."

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Houston startup wins Space Force contract to advance quantum energy generator

quantum contract

Houston-based quantum energy technology startup Casimir Inc. has been awarded an STTR Phase I contract from the U.S. Space Force's SpaceWERX to support the development of the company's solid-state generator for potential use by the Department of the Air Force.

SpaceWERX is the innovation arm of the U.S. Space Force and a division within AFWERX, the incubator and innovation arm of the United States Department of the Air Force. The Air Force Research Laboratory and SpaceWERX, along with many other government agencies, help support innovation through the Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) grants and contracts.

As part of the new contract, Casimir will work to refine a fully independent generator. Casimir’s solid-state power technology could support national security missions by providing reliable power even in difficult-to-service environments.

In May, Casimir emerged from stealth, netting a $12 million seed round to commercialize its quantum energy chip. The semiconductor chips can generate power from quantum vacuum fields without the need for batteries or charging. The company aims to include the chips in large-scale energy systems that can power homes, commercial infrastructure and electric vehicles.

“This STTR funds some analysis work to address our proposed scaling approach of making our chips multi-layer to increase aggregate power,” Harold “Sonny” White, founder and CEO of Casimir, tells Energy Capital.

White adds that the company will work with Texas A&M to develop chip planarization techniques to support Casimir’s plans to scale. Additionally, White says the company is working with the U.S. Space Force to explore more applications for its technology.

“Casimir’s technology brings a new capability to the market in the form of our persistent power chips,” White adds. “This approach will be relevant to ultra-low-power electronics, and with the scaling approach we are developing, connected with the STTR work, will eventually be relevant to consumer electronics and beyond.”

Casimir has previously reported that it plans to commercialize its first-generation MicroSparc chip by 2028. The chips are expected to power devices for years without the need for replacements.

The total funding for this project has not yet been disclosed.

Houston clean energy tax compliance platform tops the Inc. 5000 in 2026

Top of the List

Houston-based Empact Technologies has ridden the clean energy wave to the Inc. 5000’s 30 fastest-growing private companies.

With three-year revenue growth of 8,275 percent, the clean energy tax credit compliance management platform appears at No. 27 on this year’s Inc. 5000 list. The 2026 list ranks private companies based on percentage revenue growth from 2022 to 2025.

Empact Technologies, also ranks as the No. 2 fastest-growing company in Houston and the No. 4 fastest-growing company in Texas.

Originally founded by Charles Dauber in 2012, Empact Technologies relaunched in 2023 as a purpose-built tool for clean energy tax credit compliance, following the creation of the Inflation Reduction Act, the largest clean energy investment incentive in U.S. history.

It provides a platform for clean energy developers, investors, and contractors, and combines its NexusIQ AI-native compliance platform with a dedicated team of technical and regulatory experts to ensure ongoing compliance and documentation.

Empact Technologies is joined by six other Houston-area companies in the top 250 of this year's Inc. 5000, including one that made the top 10.

Here are the six other Houston-area companies that claimed spots in the top 250 on the Inc. 5000 list. Each company name is followed by its ranking, headquarters city, and three-year growth rate.

  • No. 6 Equipe Realty, 23,210 percent
  • No. 60 Action1, 4,512 percent
  • No 75 Signs By G, 3,684 percent
  • No. 79 The ’Pause Life, 3,469 percent (Galveston)
  • No. 110 Turtlebox Audio, 2,576 percent
  • No. 178 Dahnani Private Equity Group, 1,904 percent (Stafford)
Empact and fellow honorees will be recognized Oct. 14-16 at the 2026 Inc. 5000 Conference & Gala in Dallas.

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A version of this article first appeared on InnovationMap.com.

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.