Here's what energy transition companies stood out to Rice Alliance's experts. Photo via Rice Alliance

At the 20th annual Energy Tech Venture Forum presented by Rice Alliance for technology and Entrepreneurship, 11 startups scored recognition from the event's investors who evaluated over 90 early-stage energy transition companies.

"The selection process was both exhilarating and challenging given the incredible ideas we've seen today," says Jason Sidhu, director of information services business engagement at TC Energy, who announced the top companies. "I want to extend my gratitude to every company that participate din this year's Energy Tech Venture Forum. Your commitment to solving energy problems and pursuing ambitions ideas is truly commendable."

In addition to the top 10 most-promising companies, the event's attendees decided the people's choice pick out of the 50 or so pitching companies. The winner of that recognition was Calgary, Alberta-based Galatea Technologies, which has created a tech platform to enhance workflows for operational, financial, and environmental performance.

The top companies, according to the Rice Alliance experts and investors, were:

  • Circular economy startup, Polystyvert. Based in Montreal, the company has created a unique dissolution recycling process that creates a material that can contribute to cutting carbon emissions by up to 90 percent.
  • United Kingdom-based Mirico provides a tracking technology to its customers to measure climate gases (like methane, carbon dioxide, nitrous oxide, and ammonia), across areas up to half a square mile and in all conditions.
  • Protein Evolution, from New Haven, Connecticut, taps into a combination of green chemistry and enzyme technology to break down synthetic polymers.
  • Another Canadian company, Ayrton Energy, based in Calgary, created a liquid organic H2 carrier (LOHC) storage technology presents an opportunity for large, scalable and efficient transport of H2 over long distances.
  • Also representing New Haven, Connecticut, Carbon Loop is on a mission to make carbon capture and conversion scalable through carbon dioxide electrolysis using a proprietary catalyst to convert captured carbon dioxide into methanol.d
  • Based in London, Mobilus Labs has designed a new way for frontline communication with an in-helmet hardware and software solution. software solution designed for the frontline workforce.
  • 1s1 Energy, based in California, is working on producing low-cost green hydrogen by creating new materials to unlock unprecedented electrolyzer efficiency, durability, and more.
  • From Skokie, Illinois, Numat is specializing in solutions within Metal-organic framework (MOF) research to enhance the process of separating the hazardous chemicals negatively impacting human health and the environment.
  • Mantel, headquartered in Cambridge, Massachusetts, created a molten borate technology to capture CO2 in a new and efficient way.
  • The lone Houston-based company, Mars Materials is working to produce acrylonitrile using CO2 and biomass to enable decarbonization applications in carbon fiber and wastewater treatment.

Ten companies from around the world were named as most promising. Photo courtesy of Rice

Next month, 96 startups will pitch at an annual event focused on the future of energy. Here's who will be there. Photo via rice.edu

Exclusive: Rice Alliance announces participants ahead of 20th annual energy symposium

where to be

Dozens of companies will be a part of an upcoming energy-focused conference at Rice University — from climate tech startups to must-see keynote speakers.

The 20th Annual Rice Alliance Energy Tech Venture Forum will take place on September 21 at Rice University’s Jones Graduate School of Business. Anyone who's interested in learning more about the major players in the low-carbon future in Houston and beyond should join the industry leaders, investors, and promising energy and cleantech startups in attendance.

This year's keynote speakers include Christina Karapataki, partner at Breakthrough Energy Ventures, the venture capital fund backed by Bill Gates; Scott Nyquist, vice chairman at Houston Energy Transition Initiative, founded by the Greater Houston Partnership; and Jeff Tillery, COO at Veriten.

Nearly 100 startups will also be pitching throughout the day, and at the end of the program, the most-promising companies — according to investors — will be revealed. See below for the 2023 selection of companies.

Presenting companies:

  • Element Resources
  • Eugenie AI
  • Flash H2 Synthesis from Waste Plastic at Zero Net Cost
  • Fluid Efficiency
  • Galatea Technologies
  • Heimdal
  • Impact Technology SystemsAS
  • INGU
  • Lithos
  • Luminescent
  • Mantel
  • Mars Materials
  • Microgrid Labs
  • Mirico
  • Mobilus Labs
  • Muon Vision
  • Nano Nuclear
  • NobleAI
  • Numat
  • Ourobio
  • Planckton Data Technologies
  • Polystyvert
  • Princeton NuEnergy
  • Protein Evolution
  • Qult Technologies
  • Sage Geosystems
  • Salient Predictions
  • Sawback Technologies
  • SHORELINE AI
  • Solidec
  • Spectral Sensor Solutions
  • Teren
  • Terradote
  • TexPower
  • Thiozen
  • Technology from the Lab of Dr. James Tour
  • Volexion
  • Xecta

CEA Demo Day:

  • Ayrton Energy
  • Carbix
  • CryoDesalination
  • Digital Carbon Bank
  • EarthEn
  • H Quest Vanguard
  • Highwood Emissions Management
  • Icarus RT
  • Khepra
  • Natrion
  • Oceanways
  • Relyion Energy
  • Triton Anchor
  • TROES

Office hours only:

  • 1s1 Energy
  • AKOS Energy
  • Aperta Systems
  • Atargis Energy
  • Ayas
  • C-Power
  • C-Quester
  • Carbon Loop
  • Deep Anchor Solutions
  • DG Matrix
  • Drishya AI Labs
  • Earthbound.ai
  • EarthBridge Energy
  • Enoverra
  • equipcast
  • ezNG Solutions
  • Feelit Technologies
  • FluxWorks
  • Forge
  • Horne Technologies
  • Imperium Technologies
  • LiCAP Technologies
  • Make My Day
  • Moblyze
  • MyPass Global
  • NovaSpark Energy
  • Octet Scientific
  • Perceptive Sensor Technologies
  • PetroBricks
  • Piersica
  • Poseidon Minerals
  • Predyct
  • RIvotto
  • Roboze
  • Talisea
  • ThermoLift Solutions
  • Trout Software
  • Tuebor Energy
  • Undesert Corporation
  • Viridos
  • Vroom Solar
  • Well Information Technologies
  • WellWorth
  • Zsense Systems
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CultureMap Emails are Awesome

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.

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."