Twelve local startups have joined Greentown Houston, along with others from around the world. Photo courtesy Greentown Labs.

More than 40 climatetech startups joined the Greentown Labs Houston community in the second half of 2025. Twelve hail from the Bayou City.

The companies are among a group of nearly 70 that joined the climatetech incubator, which is co-located in Houston and Boston, in Q3 and Q4.

The new companies that have joined the Houston incubator specialize in a variety of clean energy applications, from green hydrogen-producing water-splitting cycles to drones that service wind turbines.

The local startups that joined Greentown Houston include:

  • Houston-based Wise Energie, which delivers turnkey microgrids that blend vertical-axis wind, solar PV, and battery storage into a single, silent system.
  • The Woodlands-based Resollant, which is developing compact, zero-emissions hydrogen and carbon reactors to provide low-cost, scalable clean hydrogen and high-purity carbon for the energy and manufacturing sectors.
  • Houston-based ClarityCastle, which designs and manufactures modular, soundproof work pods that replace traditional drywall construction with reusable, low-waste alternatives made from recycled materials.
  • Houston-based WattSto Energy, which manufactures vanadium redox flow batteries to deliver long-duration storage for both grid-scale projects and off-grid microgrids.
  • Houston-based AMPeers, which delivers advanced, high-temperature superconductors in the U.S. at a fraction of traditional costs.
  • Houston-based Biosimo, which is developing bio-based platform chemicals, pioneering sustainable chemistry for a healthier planet and economy.
  • Houston-based Ententia, which offers purpose-built, generative AI for industry.
  • Houston-based GeoKiln Energy Innovation, which is developing a new way to produce clean hydrogen by accelerating natural geologic reactions in iron-rich rock formations using precision electrical heating.
  • Houston-based Timbergrove, which builds AI and IoT solutions that connect and optimize assets—boosting visibility, safety, and efficiency.
  • Houston-based dataVediK, which combines energy-domain expertise with advanced machine learning and intelligent automation to empower organizations to achieve operational excellence and accelerate their sustainability goals.
  • Houston-based Resonant Thermal Systems, which uses a resonant energy-transfer (RET) system to extract critical minerals from industrial and natural brines without using membranes or grid electricity.
  • Houston-based Torres Orbital Mining (TOM),which develops autonomous excavation systems for extreme environments on Earth and the moon, enabling safe, data-driven resource recovery and laying the groundwork for sustainable off-world industry.

Other startups from around the world joined the Houston incubator in the same time period, including:

More than 100 startups joined Greentown this year, according to an end-of-year reflection shared by Greentown CEO Georgina Campbell Flatter.

Flatter joined Greentown in the top leadership role in February 2025. She succeeded former CEO and president Kevin Knobloch, who stepped down in July 2024.

"I moved back to the United States in March 2025 after six years overseas—2,000 miles, three children, and one very patient husband later. Over these months, I’ve had the chance to hear from the entrepreneurs, industry leaders, investors, and partners who make this community thrive. What I’ve experienced has left me brimming with urgent optimism for the future we’re building together," she said in the release.

According to Flatter, Greentown alumni raised more than $2 billion this year and created more than 3,000 jobs.

"Greentown startups and ecosystem leaders—from Boston, Houston, and beyond—are showing that we can move further and faster together. That we don’t have to choose between more energy or lower emissions, or between increasing sustainability and boosting profit. I call this the power of 'and,'" Flatter added. "We’re working for energy and climate, innovation and scale, legacy industry and startups, prosperity for people and planet. The 'and' is where possibility expands."

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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.

Houston energy co. names new COO to scale offshore decommissioning

new hire

Houston-based Promethean Energy has named a new COO as it looks to scale.

Martyn Fear, former CEO of Altamesa Energy Canada Inc., will assume the role, the company announced last week. He brings decades of experience at energy companies such as BP and Maersk Oil and has held board positions at several private equity and venture-backed firms.

“Promethean has built a differentiated platform for managing and retiring late-life assets safely, efficiently, and responsibly,” Fear said in a news release. “The industry is facing a structural shift as decommissioning moves to the forefront, and the opportunity to combine operational excellence, disciplined project delivery, and innovative commercial models is incredibly compelling."

Promethean has developed an environmentally sustainable, integrated model for late-life asset management and offshore well decommissioning. Fear will oversee day-to-day operations at Promethean and the execution of this integrated operator-service model as the company looks to scale and expand to new markets.

“Martyn is a proven leader with a deep operational track record and a passion for building high-performance, safety-first organizations,” Aditya Singh, Promethean's CEO, added in the release. “As Promethean enters its next phase—scaling our integrated operator-service model and delivering first-time-right decommissioning at pace—his experience in transforming complex asset portfolios and leading global teams makes him the ideal COO to drive operational execution while we continue to advance our strategic vision.”

Last May, the company successfully decommissioned offshore orphaned wells in the Matagorda Island lease area. In November, it also announced that it had completed a multi-client project to safely plug and abandon an orphaned well on a storm-damaged platform in the South Timbalier lease area.

Both projects were based in the Gulf of Mexico, where Promethean is looking to grow.