New global report names top cleantech startups to keep an eye on

seeing green

Fervo Energy — and a few other Greentown Labs companies — made a global list of clean tech companies. Photo via fervoenergy.com

Nine Greentown Labs members were recognized on a global list honoring cleantech companies.

Houston-based Fervo Energy was named to Cleantech Group’s Global Cleantech 100 report. Cleantech Group is a research-driven company that aids the public sector, private sector, investors, and also identifies, assesses, and engages with the innovative solutions around climate challenges.

Fervo, a geothermal energy company that specializes in a renewable energy technology that uses hot water to produce electricity, debuted in 2022 on the list, and was honored in the “Energy & Power” category for the second straight year.

The other Greentown Labs, which is dual located in Houston and Somerville, Massachusetts, companies recognized on the list include:

Amogy, a New York-based novel carbon-free energy system using ammonia as a renewable fuel
Carbon Upcycling Technologies, a Canadian waste and carbon utilization company
Dandelion Energy, New York-based company offering ground source heat pumps for most homes
Energy Dome, a Milan-based company addressing the problem of long-duration energy storage
e-Zinc, a Canadian company with a breakthrough electrochemical technology for energy storage
Nth Cycle, a Massachusetts company with sustainable metal refining
Raptor Maps, a Massachusetts company with a software platform for solar assets' performance data management
Sublime Systems, a Massachusetts companydeveloping a breakthrough process for low-carbon cement
WeaveGrid, a California company working with utilities, automakers, EVSEs, and EV owners to enable and accelerate the electrification of transportation

The number of nominations from the public, a panel, i3, awards and Cleantech Group totaled 25,435 from over 65 countries, which is a 61% increase from the 2023 nomination process. Winners were chosen from a short list of 330 companies by a panel of over 80 industry experts.

While not on the list, Beaumont-based Fortress Energy was mentioned for its electrolyzer supply agreement with Cleantech Group 100 winner Electric Hydrogen.

The Cleantech Group 100 was started 15 years ago.

“In 15 more years, we will be at 2039—by which time, a mere decade out from the ‘net-zero’ target of 2050,” Cleantech Group CEO Richard Youngman says in the report. “I would expect the composition of our annual list to have markedly changed again, and the leading upcoming private companies of that time to reflect such.”

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Houston researcher develops efficient method to cool AI data centers

cool findings

A University of Houston professor has developed a new cooling method that can remove heat at least three times more effectively from AI data centers than current technologies.

Hadi Ghasemi, a distinguished professor of Mechanical & Aerospace Engineering at UH, published his findings in two articles in the International Journal of Heat and Mass Transfer. The findings solve a critical issue in the growing AI sector, according to UH.

High-powered AI data centers generate huge amounts of heat due to the GPU and operating systems they use with extreme power densities, which introduce complex thermal challenges. Traditionally, cooling methods, like microchannels, which use flow and spray cooling, have had limitations when exposed to extreme heat flux, according to UH.

Ghasemi’s research, however, found a more effective way to design thin-film evaporation structures to release heat from data centers and electronics at record performance.

Ghasem’s solution coupled topology optimization and AI modeling to determine the best shapes for thin film efficiency, ultimately landing on a branch-like structure—resembling a tree.

The model found that the “branches” needed to be about 50 percent solid and 50 percent empty space for optimum efficiency, and that they could sustain high heat fluxes with minimal thermal resistance.

“These structures could achieve high critical heat flux at much lower superheat compared to traditionally studied structures,” Ghasemi said in a news release. “The new structures can remove heat without having to get as hot as previous removal systems.

Ghasemi’s doctoral candidates, Amirmohammad Jahanbakhsh and Saber Badkoobeh Hezave, also worked on the project. The team believes their results show the impact of a physics-aware, AI design and can help ensure reliability, longevity and stability of AI data centers.

“Beyond achieving record performance, these new findings provide fundamental insight into the governing heat-transfer physics and establishes a rational pathway toward even higher thermal dissipation capacities,” Ghasemi added in the release

Texas federal judge allows lawsuit against California AG over ExxonMobil remarks

In the News

A federal judge in Texas ruled that ExxonMobil can bring a defamation lawsuit against California’s attorney general over comments about the company’s plastic recycling efforts.

U.S. District Judge Michael J. Truncale in the Eastern District of Texas said in a ruling in February that California Attorney General Rob Bonta cannot claim official immunity in regards to several statements he made, including one in a campaign email sent to Texas residents.

Bonta sued Exxon in September 2024, saying that the oil giant encouraged consumers to purchase plastics products with the promise that the products would be recycled. He said less than 5% of plastic is recycled into another plastic product, and that recycling processes touted by Exxon don't work. Exxon said the problem is with California's recycling system.

Exxon later sued Bonta in his individual capacity and environmental groups for defamation, saying that the comments harmed current and future business contracts. The lawsuit was filed in Texas, near its principal place of business.

Truncale dismissed the lawsuit against the environmental groups but allowed it to proceed against Bonta.

The judge pointed to a campaign email Bonta sent to Texas residents saying that only 5% is recycled and the rest ends up in the environment and in our bodies: “Exxon Mobil knew, and Exxon Mobil lied.” Bonta, a Democrat, argued he was simply updating email recipients on his office's activities.

But Truncale said a campaign contribution link on the email turned the communication into a campaign activity not protected by immunity in Bonta's official capacity as attorney general.

“Here, the contribution request betrays the email's true nature: a campaign promotion. Campaigning is not within Bonta's scope of employment,” the judge wrote.

Bonta has filed a notice of appeal.

“The Attorney General looks forward to vigorously litigating this case, and is proud to advance his lawsuit against ExxonMobil,” his press office said.

ExxonMobil said in a statement that the “campaign of lies designed to derail our advanced recycling business must stop.”

Houston startup debuts sustainable, bio-based 'leather' fashions

sustainable fashion

Last month, Houston-based Rheom Materials and India’s conscious design studio Econock unveiled a collaborative capsule collection that signaled more than just a product launch.

Hosted at Lineapelle—long considered the global epicenter of the world's premier leather supply chain—in the vaulted exhibition halls of Rho-Fiera Milano, the collection centered around Rheom’s 91 percent bio-based leather alternative, Shorai.

It was a bold move, one that shifted sustainability from a concept discussed in panel sessions to garments that buyers could touch and wear.

The collection featured a bomber-style jacket, an asymmetrical skirt and a suite of accessories—all fabricated from Shorai.

The standout piece, a sculptural jacket featuring a funnel neck and dual-zip closure, was designed for movement, challenging assumptions about performance limitations in bio-based materials. The design of the asymmetrical skirt was drawn from Indian armored warrior traditions, according to Rheom, with biodegradable corozo fasteners.

Built as a modular wardrobe rather than isolated pieces, the collection reflects a shared belief between Rheom and Econock in designing objects that adapt to daily life, according to the companies.

The collection was born out of a new partnership between Rheom and Econock, focused on bringing biobased materials to the market. According to Rheom, the partnership solves a problem that has stalled the adoption of many next-gen textiles: supply chain friction.

While Rheom focuses on engineering scalable bio-based materials, New Delhi-based Econock brings the complementary design and manufacturing ecosystem that integrates artisans, circular materials and production expertise to translate the innovative material into finished goods.

"This partnership removes one of the biggest barriers brands face when adopting next-generation materials,” Megan Beck, Rheom’s director of product, shared in a news release. “By reducing friction across the supply chain, Rheom can connect brands directly with manufacturers who already know how to work with Shorai, making the transition to more sustainable materials far more accessible.”

Sanyam Kapur, advisor of growth and impact at Econock, added: “Our partnership with Rheom Materials represents the benchmark of responsible design where next-gen materials meet craft, creativity, and real-world scalability.”

Rheom, formerly known as Bucha Bio, has developed Shorai, a sustainable leather alternative that can be used for apparel, accessories, car interiors and more; and Benree, an alternative to plastic without the carbon footprint. In 2025, Rheom was a finalist for Startup of the Year in the Houston Innovation Awards.

Shorai is already used by fashion lines like Wuxly and LuckyNelly, according to Rheom. The company scaled production of the sugar-based material last year and says it is now produced in rolls that brands can take to market with the right manufacturer.

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This article originally appeared on our sister site, InnovationMap.

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