Ten climatetech startups were named most-promising at this annual Rice Alliance Energy Tech Venture Forum. Photo courtesy Rice Alliance.

Investors at the Rice Alliance Energy Tech Venture Forum have named the 10 most-promising startups among the group of 100 clean tech companies participating in the event.

The 22nd annual event was held yesterday, Sept. 18, at Rice University’s Jones Graduate School of Business and was part of the second Houston Energy and Climate Startup Week.

The most-promising startups will receive $7,000 in in-kind legal services from Baker Botts.

The 10 most-promising companies included:

  • Houston-based Xplorobot, which has developed laser gas imaging technology for the first handheld methane detection device approved by the EPA as an alternative test method
  • Seattle-based Badwater Alchemy, a desalination company that uses nano materials to purify saline water at a fraction of the cost of traditional methods
  • San Francisco-based Ammobia, which is developing a clean ammonia production process
  • Illinois-based Celadyne Technologies, which is building hydrogen for industrial decarbonization with durable and efficient fuel cells and electrolyzers
  • Massachusetts-based MacroCycle Technologies, which converts plastic waste in the form of bottles, food trays and polyester textiles into virgin-grade mPET resin
  • Massachusetts-based AtoMe, which uses nano-ceramics to develop ultra-durable metals for 3D printing
  • Colorado-based Advanced Thermovoltaic Systems (ATS) Energy, a renewable energy semiconductor manufacturing company
  • North Carolina-based Lukera Energy, which is converting waste methane into high-value fuel
  • Midland, Texas-based AI Driller, a company that uses AI and machine learning to enable remote operations and provide historical drilling data for survey management, anti-collision monitoring and iob reporting
  • New York-based Fast Metals Inc., which has developed a chemical process to extract valuable metals from complex toxic mine tailings that is capable of producing iron, aluminum, scandium, titanium and other rare earth elements using industrial waste and waste CO2 as inputs

Arculus Solutions won the People's Choice Award. The New Jersey-based company retrofits natural gas pipelines for safe hydrogen transportation. It also won Track A: Hydrogen, Fuel Cells, Buildings, Water, & Other Energy Solutions at the Energy Venture Day and Pitch Competition during CERAWeek earlier this year.

The 100 energy technology ventures selected to participate in the forum were named earlier this year. See the full list here.

Houston Energy and Climate Startup Week returns Sept. 15-19. Photo via rice.edu

8+ can't-miss events at Houston Energy and Climate Startup Week 2025

where to be

Editor's note: This article may be updated to include additional events.

The second annual Houston Energy and Climate Startup Week is less than a month away—and the calendar of events is taking shape.

The series of panels, happy hours and pitch days will take place Sept. 15-19. The Ion District will host many of the week's events.

Here are the details on some of the can't-miss events of the week:

Houston Energy & Climate Startup Week Kickoff Panel and Block Party

Join fellow innovators, founders, investors and energy leaders at this kick-off event hosted by The Ion and HETI, which will feature brief welcome remarks, a panel discussion and networking, followed by a block party on the Ion Plaza.

This event is Monday, Sept. 15, at 4 p.m. at The Ion. Register here.

Energytech Nexus Pilotathon

Grab breakfast and take in keynotes and panels by leaders from New Climate Ventures, V1 Climate, Halliburton, Energy Tech Nexus and many others. Then hear pitches during the Pilotathon, which targets startups ready to implement pilot projects within six to 12 months.

This event is Tuesday, Sept. 16, from 8 a.m.-5 p.m. at GreenStreet. Get tickets here.

Meet the Activate Houston Cohort 2025 Fellows

Meet Activate's latest cohort, which was named this summer, and also learn more about its 2024 group.

This event is Tuesday, Sept. 16, at 5 p.m. at the Ion. Register here.

New Climate Ventures Afterparty

Enjoy music, networking and carbon-negative spirits at Axelrad. Houston startups Quaise Energy, Solidec, Dimensional Energy, Rheom Materials, and Active Surfaces will also be on-site.

This event is Tuesday, Sept. 16, from 6:30-9:30 p.m. at Axelrad. Register here.

Green ICU Conference: Sustainability in Health Care for a Healthier Future

Houston Methodist will host its inaugural Green ICU Conference during Houston Energy & Climate Week. The conference is designed to bring together healthcare professionals, industry leaders, policymakers and innovators to explore solutions for building a more sustainable healthcare system.

This event is Wednesday, Sept. 17. from 8 a.m.-3 p.m. at TMC Helix Park. Register here.

Rice Alliance Energy Tech Venture Forum

Hear from clean energy startups from nine countries and 19 states at the 22nd annual Energy Tech Venture Forum. The 12 companies that were named to Class 5 of the Rice Alliance Clean Energy Accelerator will present during Demo Day to wrap up their 10-week program. Apart from pitches, this event will also host keynotes from Arjun Murti, partner of energy macro and policy at Veriten, and Susan Schofer, partner at HAX and chief science officer at SOSV. Panels will focus on corporate innovation and institutional venture capital.

This event is Thursday, Sept. 18, from 7:30 a.m.-5 p.m. at Rice University’s Jones Graduate School of Business. Register here.

Shell STCH Open House

Get a behind-the-scenes look at how Shell is leveraging open innovation to scale climate tech. The open house will spotlight two Houston-based startups—Mars Materials, which converts captured CO2 into acrylonitrile, and DexMat, which transforms methane into high-performance carbon nanotube fibers.

This event is Thursday, Sept. 18, from 8:30 a.m.-12:15 p.m. at Shell Technology Center. Register here.

ACCEL Year 3 Showcase

Celebrate Advancing Climatetech and Clean Energy Leaders Program, or ACCEL, an accelerator program for startups led by BIPOC and other underrepresented founders from Greentown Labs and Browning the Green Space. Two Houston companies and one from Austin are among the eight startups to be named to the 2025 group. Hear startup pitches from the cohort, and from Greentown's Head of Houston, Lawson Gow, CEO Georgina Campbell Flatter and others.

This event is Thursday, Sept. 18, from 5-8 p.m. at Greentown Labs. Get tickets here.

Halliburton Labs Finalists Pitch Day

Hear from Halliburton Labs' latest cohort of entrepreneurs. The incubator aims to advance the companies’ commercialization with support from Halliburton's network, facilities and financing opportunities. Its latest cohort includes one company from Texas.

This event is Friday, Sept. 19, from 8 a.m.-noon at The Ion. Register here.

Chevron Energy Innovation Finals

The University of Houston will present the 4th Annual Chevron Innovation Commercialization Competition.

The event is Friday, Sept. 19, from 10 a.m.-1:30 p.m. at the University of Houston. Register here.

Houston Energy and Climate Startup Week was founded in 2024 by Rice Alliance for Technology and Entrepreneurship, Halliburton Labs, Greentown Labs, Houston Energy Transition Initiative (HETI), Digital Wildcatters and Activate.

Last year, Houston Energy and Climate Startup Week welcomed more than 2,000 attendees, investors and industry leaders to more than 30 events. It featured more than 100 speakers and showcased more than 125 startups.





Houston Energy and Climate Startup Week is coming back for a second year. Photo via GHP

Houston Energy and Climate Startup Week announces 2025 dates, key events

comeback tour

Six local organizations focused on the energy transition have teamed up to bring back Houston Energy and Climate Startup Week.

The second annual event will take place Sept. 15-19, according to an announcement. The Ion District will host many of the week's events.

Houston Energy and Climate Startup Week was founded in 2024 by Rice Alliance for Technology and Entrepreneurship, Halliburton Labs, Greentown Labs, Houston Energy Transition Initiative (HETI), Digital Wildcatters and Activate.

“Houston Energy and Climate Startup Week was created to answer a fundamental question: Can we achieve more by working together than we can alone?” Jane Stricker, senior vice president at the Greater Houston Partnership and executive director of HETI, said in the release.

So far, events for the 2025 Houston Energy and Climate Startup Week include an introduction to climatetech accelerator Activate's latest cohort, the Rice Alliance Energy Tech Venture Forum, a showcase from Greentown Labs' ACCEL cohort, and Halliburton Labs Pitch Day.

Houston organizations New Climate Ventures and Digital Wildcatters, along with Global Corporate Venturing, are slated to offer programming again in 2025. And new partners, Avatar Innovations and Decarbonization Partners, are slated to introduce events. Find a full schedule here.

Other organizations can begin entering calendar submissions starting in May, according to the release.

Last year, Houston Energy and Climate Startup Week welcomed more than 2,000 attendees, investors and industry leaders to more than 30 events. It featured more than 100 speakers and showcased more than 125 startups.

"In 2024, we set out to build something with lasting impact—rooted in the ingenuity of Houston’s technologists and founders. Thanks to a collaborative effort across industry, academia, and startups, we’ve only just begun to showcase Houston’s strengths and invite others to be part of this movement," Stricker added in the release. "We can’t wait to see the city rise to the occasion again in 2025.”

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Houston startup secures $5M to turn oilfield wastewater into critical minerals

fresh funding

Houston-based startup Altillion has secured $5 million in seed funding to accelerate the commercialization of its proprietary IRIS and ALIX technologies, which convert oilfield-produced water into valuable minerals.

San Francisco-based EIC Rose Rock and Houston-based Flathead Forge led the round. Altillion says the funding will go toward pilot facilities and commercial deployments as the company looks to scale in the U.S.

“Altillion’s efficient and scalable technologies are needed more than ever to reshape critical mineral recovery and facilitate beneficial use of oilfield brines,” Jay Keener, Altillion’s CEO and co-founder, said in a news release. “We’re uniquely positioned to provide a stable, domestic supply of the critical minerals needed for electronics, batteries, healthcare and national defense technologies. This investment from EIC Rose Rock and Flathead Forge enables us to strategically accelerate this impact and is very timely given the current geopolitical dynamics.”

Altillion's IRIS and ALIX platforms extract minerals like iodine, lithium and copper from oilfield-produced water, geothermal brines and salars. This process allows companies to unlock new sources of revenue while also boosting the domestic critical minerals supply chain. The company announced earlier this summer that it will launch a feasibility project in the Permian Basin and aims to develop a path to commercial-scale implementation in the field.

“We are excited to partner with Altillion to scale and deploy these world-class technologies to access the vast wealth hidden in wastewater,” David Clouse, Managing Director of EIC Rose Rock, added in the release. “With Altillion, we’re expanding our ability to empower the energy industry to domestically source the critical minerals America needs for a robust economy and supply chain.”

Altillion was founded by Keener and COO Scott Buckwald in 2023. Keener previously founded KDH Trading, where Buckwald also serves as COO, according to his LinkedIn page.

Houston's KBR to provide tech for Singapore SAF plant

SAF agreement

Houston engineering and technology contractor KBR has been picked as the technology provider for what’s expected to be Asia's first commercial-scale ethanol-to-jet sustainable aviation fuel (SAF) plant.

The proposed plant on Jurong Island in Singapore is being developed by Keppel Ltd.’s Infrastructure Division and Aster Chemicals and Energy. KBR will provide technology licensing and Front-End Engineering Design (FEED) services based on its PureSAF technology.

The plant has a planned production capacity of up to 100,000 tons of SAF per year. The plant is subject to final investment decisions and regulatory approvals.

“We are looking forward to working with Keppel and Aster on this key project and to support Singapore’s ambition of becoming Asia’s leading SAF hub and advancing the ongoing efforts to decarbonize the country’s aviation ecosystem,” Stuart Bradie, KBR president and CEO, said in a news release.

According to KBR, its PureSAF Technology can process multiple feedstocks like bioethanol, syngas, carbon dioxide and hydrogen and convert them to SAF, diesel and gasoline.

The technology was developed by Swedish Biofuels AB and commercialized by KBR.

“KBR’s PureSAF is a feedstock-flexible, bankable technology that is designed to deliver a 100% drop in jet fuel, ready to power aircraft without blending,” Bradie added in the news release. “We are constantly innovating our SAF solution to make it compatible with feedstock availability in different regions and to enable the aviation industry to transition to low-carbon jet fuel with a cost-optimized approach.

KBR has also entered into a memorandum of intent with Keppel’s Infrastructure Division, which states that the companies will collaborate again on decarbonization efforts across biofuels, plastic recycling, digitalization via AI, and SAF.

KBR announced in October that it would spin off its Mission Technology Solutions business, nicknamed SpinCo. The scaled-down KBR, nicknamed RemainCo, would concentrate solely on sustainability technology and services designed to reduce carbon emissions and support energy transition efforts. SpinCo named its new CEO and CFO earlier this month.

Houston energy expert discusses why hydrogen still has a future

Guets Column

Not long ago, hydrogen was hailed as the next big thing in clean energy. Investors poured in, and countries from Japan to Germany built ambitious hydrogen strategies. It wasn’t a new discovery; hydrogen has been used for over a century in refineries and fertilizers, but it suddenly found itself reborn as the world began working toward decarbonization.

When hydrogen burns, the only byproduct is water. Green hydrogen, produced with renewable power, could replace fossil fuels in everything from trucks to ships to steel mills. But the momentum has cooled. Costs remain stubbornly high, several projects have been delayed or canceled, and policy support has wavered. In the U.S., a change in administration has created uncertainty. In Europe, some governments are slowing funding or revising hydrogen mandates. Even the International Maritime Organization (IMO) recently postponed a key vote on fuel-carbon standards.

Yet as Mike Graff , former Chairman and CEO of American Air Liquide, said in an Energy Forum episode with Ed Emmett at Rice University’s Baker Institute, “The world is always looking to make sure that energy is first available, it’s affordable, and then it’s clean. And I see hydrogen over time evolving in that manner.” He also noted that “companies have produced hydrogen and utilized hydrogen for over 100 years, and they’ve done that very safely… I think we can continue that moving forward.”

China has doubled down on hydrogen as part of its industrial strategy, building massive electrolyzer manufacturing capacity and funding dozens of pilot projects across transportation and heavy industry. Japan and South Korea also stand out as examples of how sustained policy support can drive hydrogen progress.

Where Hydrogen Fits Today

To understand hydrogen’s role now, it helps to remember what it actually does. About 76 percent of global hydrogen is produced from natural gas and used in refineries, fertilizer plants, and chemical production. This so-called “gray hydrogen” is essential but carbon-intensive.

What’s new is the rise of low-carbon hydrogen, “blue” hydrogen made from natural gas with carbon capture, and “green” hydrogen produced by splitting water with renewable electricity. These methods are expensive, but they’re growing. According to the International Energy Agency, global low-emissions hydrogen output rose about 10 percent in 2024.

Hydrogen is also expanding beyond industry. As Graff explained, it already powers thousands of forklifts in warehouses across the U.S. and is beginning to appear in commercial trucking, locomotives, and even aviation prototypes. “You can now drive 600 to 800 miles on a hydrogen fuel-cell truck,” he noted, “and refuel in 30 minutes, just like you would refill for diesel.”

The Cost Challenge and a Gulf Coast Opportunity

So why the slowdown? One word: economics.

Even with generous tax credits, green hydrogen can cost two to three times more than conventional fuels. Electrolyzers are still expensive, though costs are falling as Chinese suppliers introduce low-cost alternatives.

Infrastructure is another hurdle. Pipelines, storage, and fueling networks need to be built from scratch.

But those same challenges point to opportunity, especially along the U.S. Gulf Coast. The region already has one of the world’s largest hydrogen pipeline systems and a well-established energy infrastructure. Texas, in particular, has a head start. It already hosts nearly 1,000 miles of hydrogen pipelines, about 64 percent of the U.S. total, and some of the world’s largest hydrogen storage sites at Moss Bluff, Spindletop, and Clemens. Out of 140 hydrogen plants operating nationwide, 43 are in Texas, supported by extensive refining and natural gas infrastructure. This combination of assets gives the Gulf Coast an unmatched foundation to scale low-carbon hydrogen and integrate production, storage, and end use across industries.

As Ken Medlock , Senior Director of the Center for Energy Studies at Rice University’s Baker Institute, explains in his report: Developing a Robust Hydrogen Market in Texas, Texas has all the critical elements needed to lead in a low-carbon hydrogen economy, including existing infrastructure, a skilled workforce, and proximity to industrial demand centers. That combination gives it a distinct advantage in scaling up hydrogen production and use.

Governments around the world are showing renewed confidence in hydrogen. The European Commission awarded nearly €3 billion to 13 major projects, while Japan and South Korea continue expanding fueling networks. China is leading one of the most ambitious buildouts, with more than 50 planned hydrogen projects and a rapidly growing fleet of fuel-cell vehicles. Despite recent setbacks, global investment has surpassed $100 billion, and projects in places such as Chile, where strong renewables and low-cost Chinese equipment help make projects feasible, are moving toward final investment decisions.

What Comes Next

Hydrogen’s future won’t depend on replacing every fuel, but on filling the gaps where batteries and biofuels fall short.

Transportation: This is where momentum is strongest today. Batteries dominate cars, but hydrogen fuel cells excel in heavy trucks, ships, and planes. As Graff noted, “You can design a commercial vehicle with the same utility as diesel but powered by hydrogen.” Airbus and Boeing are testing hydrogen propulsion concepts, and several ports are experimenting with hydrogen bunkering for cargo ships.

Industry: Steel, cement, and chemicals account for a quarter of global emissions. Hydrogen-based direct-reduced-iron (DRI) steelmaking is being piloted in Europe and Asia and could transform how these materials are produced at scale.

Storage: Hydrogen can store energy for days or weeks, serving as backup for renewables like wind and solar. But storage remains very costly and may only prove viable for the “last mile” of greenhouse gas reduction or grid stability.

These uses may sound niche, but that’s how technologies scale. They start small, gain an economic foothold, and expand as costs decline.

Conclusion

Hydrogen's early, perhaps irrational, exuberance may have cooled, but amidst the rubble of cancelled projects are the beginnings of an industry that could play a vital niche role on the journey towards a lower carbon intensity energy future. As costs fall and infrastructure around the world expands, hydrogen's role will expand into the nooks and crannies of the energy industry.

It won't replace every fuel, but it doesn't have to. Success will come from steady, project-by-project progress.

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Scott Nyquist is a senior advisor at McKinsey & Company and vice chairman, Houston Energy Transition Initiative of the Greater Houston Partnership. The views expressed herein are Nyquist's own and not those of McKinsey & Company or of the Greater Houston Partnership. This article originally appeared on LinkedIn.