Five companies have joined Greentown Labs Houston, specializing in various "green" applications, from converting plastic waste into sustainable materials to developing energy-storage solutions. Photo courtesy Greentown Labs.

Greentown Labs announced that it added five startups to its Houston community in Q1 of 2025.

The companies are among a group of 19 that joined the climatetech incubator, which is co-located in Houston and Boston, in the same time period. The companies that joined the Houston-based lab specialize in a number of "green" applications, from converting plastic waste into sustainable materials to developing energy-storage solutions.

The new Houston members include:

  • Concept Loop, a project of Pakistan-based Innova8e Inc., aims to repurpose post-industrial and post-consumer plastic waste into sustainable building materials.
  • GeoFuels, a Sugar Land-based company that produces hydrogen by using baseload geothermal power and methane pyrolysis.
  • PLASENE, a Houston-based company with an innovative platform that converts plastic waste into liquid fuel and low-carbon hydrogen through its proprietary catalysts and modular, scalable, pre-engineered units platform. The company was named to Greentown's ACCEL Year 3 cohort earlier this year.
  • RepAir Carbon, an Israeli company with a fully electric, zero-heat carbon-removal technology that consumes minimal energy, operates without liquids or solvents, and produces no hazardous materials or waste.
  • RotorVault from Pasadena, California, is commercializing energy-storage and load-following solutions that are containerized, modular, and field-deployable systems built on flywheel technology.

Fourteen other companies will join Greentown Boston's incubator. See the full list here.

PLASENE and five other new members—Thola, Respire Energy, Andros Innovations, FAST Metals and Tato Labs—join Greentown Labs through its most recent Advancing Climatetech and Clean Energy Leaders Program, or ACCEL, cohort. ACCEL, which works to advance BIPOC-led startups in the climatetech space, announced its third cohort last month.

From potato-starch-based bioplastics startups to companies developing carbon-coated silicon anodes, here's who's joining Greentown Labs and Browning the Green Space's ACCEL program. Photo via browningthegreenspace.org

2 Houston startups join Greentown Labs' BIPOC-led accelerator program

seeing green

Greentown Labs and Browning the Green Space announced the newest cohort for its Advancing Climatetech and Clean Energy Leaders Program, or ACCEL, which works to advance BIPOC-led startups in the climatetech space.

Two Houston companies and one from Austin are among the eight startups to be named to the 2025 group.

“The startups selected for the third ACCEL cohort represent a phenomenal range of energy and climatetech innovations, which underscores our belief that everyone and many solutions must play a role in our community’s collective decarbonization efforts,” Georgina Campbell Flatter, Greentown’s new CEO, said in a release. “We’re proud to welcome these entrepreneurs to our community and eager to see all they’ll achieve throughout the program and beyond!”

Each of the early-stage startups within the cohort will receive $25,000 in non-dilutive grant funding and participate in the year-long program focused on product and technology development, market development, fundraising and management, and team development, according to Greentown. The curriculum is led by VentureWell, a nonprofit with expertise in venture development in climatetech.

The Houston companies include:

  • Carbonext, founded by Olanrewaju Tanimola. The company is leveraging its proprietary, off-the-shelf 3D-graphene technology to develop integrated solutions with carbon-coated silicon anodes to address challenges in the graphite ecosystem, as well as lithium-battery anodes.
  • PLASENE, founded by Sohel Shaikh, Alper Gulludag and Romolo Raciti. The company offers an innovative platform that converts plastic waste into liquid fuel and low-carbon hydrogen through its proprietary catalysts and modular, scalable, pre-engineered units

The remaining six companies are:

  • Inductive Robotics, founded in Austin by Madhav Ayyagari and David Alspaugh. The startup deploys autonomous robots that deliver EV charging directly to parked vehicles in commercial parking facilities, using a subscription-based model.
  • Andros Innovations, founded in Cambridge, Massachusetts by Laron Burrows. The startup has developed a reactor that produces ammonia more cheaply, cleanly and safely than traditional methods do.
  • FAST Metals, founded in Worcester, Massachusetts by Sumedh Gostu and Anthony Staley. It has developed a hydrometallurgical-recovery process capable of extracting iron, aluminum, scandium, titanium, and other rare-earth elements from industrial tailings.
  • Respire Energy, founded in Boston by Dave Hsu, Xiaowei Teng, and Candy Wong. The energy storage startup has developed a safe, low-cost, and long-duration metal-air battery designed for microgrids.
  • Tato Labs, founded in Brooklyn by Mecca McDonald and Mia Dunn. It is developing scalable, innovative, bioplastic products and packaging solutions that leverage potato starch, protect and preserve the natural ecosystem, and minimize plastic waste.
  • Thola, founded in Portland, Maine, by Nneile Nkholise and Lerato Takana. The company provides an on-demand marketplace for commercial-building sustainability and safety management, with a mission to decarbonize old buildings.

ACCEL is supported by the Massachusetts Clean Energy Center (MassCEC), Shell, Equinor, the Growth Capital Division of MassDevelopment, Microsoft and the Barr Foundation.

The accelerator has supported 13 early-stage startups since it was founded in 2023, resulting in $325,000 in grant funding. Houston companies have been represented in each cohort. Click here to see the 2024 cohort and here to see the inaugural 2023 cohort.

Ad Placement 300x100
Ad Placement 300x600

CultureMap Emails are Awesome

Greentown Labs combines forces with MassChallenge to support more climate startups

strategic partnership

Climatetech incubator Greentown Labs has formed a strategic partnership with global zero-equity accelerator MassChallenge.

The two organizations have headquarters in the Boston area, while Greentown Labs is also co-located in Houston. MassChallenge has a hub in Dallas, as well as others in Israel, Switzerland and the United Kingdom.

The new partnership aims to strengthen the ecosystem for early-stage climatetech startups by providing more mentorship, support and a broader commercialization network for members, according to a news release.

Greentown Labs will share its expertise with the 23 startups in MassChallenge's first climate-specific accelerator, known as the MassChallenge Early Stage Climate program. Additionally, Greentown Labs members will benefit from MassChallenge's network of expert mentors, judges, entrepreneurs, partners, investors, philanthropists and others.

“There are so many synergies and shared values between MassChallenge and Greentown that launching a collaboration like this feels like a natural next step for our organizations as we strive to support as many early-stage climate founders as possible,” Georgina Campbell Flatter, Greentown Labs CEO, said in the news release. “We want to reduce the friction and barriers to market for these climate entrepreneurs and ultimately increase their opportunity for success—ecosystem collaboration is an essential part of solving these challenges together.”

Combined, Greentown and MassChallenge report that they have supported more than 4,500 founders and more than 1,000 climate startups. MassChallenge has awarded more than $18 million in equity-free grants to startups, which have gone on to raise over $15 billion, since it was founded in 2009. Greentown Labs has helped more than 575 startups raise more than $8.2 billion in funding since it launched in 2011.

Greentown recently added five startups to its Houston community and 14 other climatetech ventures to its Boston incubator. It also announced its third ACCEL cohort, which works to advance BIPOC-led startups in the climatetech space, earlier this year. Read more here.

Houston cleantech accelerator names 12 startups to 2025 cohort

early-stage accelerator

The Rice Alliance Clean Energy Accelerator has named 12 early-stage startups to its latest cohort.

The hybrid program, which operates in a hybrid capacity based out of the Ion, runs for 10 weeks and provides energy transition startups with training focused on fundraising, pilots, partnerships and sale. It begins July 8 and will be led by executive director Kerri Smith and program director Matthew Peña with support from executives-in-residence Lynn Frostman, John Jeffers, David Horsup and Dev Motiram.

The accelerator will culminate with a demo day on Sept. 18 at the Rice Alliance Energy Tech Venture Forum during the Houston Energy and Climate Startup Week.

Members of this year's cohort come from the Houston area as well as across the U.S. and Canada.

Class 5 for the Rice Alliance Clean Energy Accelerator includes:

  • Aqua-Cell Energy, which builds industrial-scale overnight batteries to provide affordable solar power
  • Arculus, a company that provides multilayer internal coating for pipelines that lowers friction, extends pipeline life and enables carbon dioxide transport and hydrogen blending
  • AtmoSpark, a Houston-based sustainable cooling and freshwater company that provides an electric field-driven air separation system that reduces dehumidification energy costs for data centers and industrial facilities
  • AtoMe, which delivers durable metallic composites to energy and aerospace companies using an eco-friendly dry blade method that eliminates harmful chemicals
  • ConceptLoop, a company that converts plastic waste into eco-friendly, low-carbon aggregate
  • Fathom Storage, which provides a more solidly embedded and steel-efficient anchoring solution for offshore service providers, wind energy developers and research institutes
  • GeoKiln, a Houston-based company that addresses issues of subsurface hydrogen extraction by applying proven oil and gas techniques to accelerate natural hydrogen reactions, enabling hydrogen production
  • Innowind Energy Solutions, a company that provides nonintrusive, active flow control devices to boost energy production and extend turbine lifespan
  • Lukera Energy, which transforms waste methane into high-value methanol using a breakthrough nanobubble technology
  • Metal Light Inc., which has developed a scalable, cost-effective Metal-Air generator to replace diesel generators
  • Moonshot Hydrogen, a company that converts food and agricultural waste into clean hydrogen and bioethanol
  • Resollant, a Woodlands-based company that delivers compact, zero-emission hydrogen and carbon reactors to refineries, petrochemical plants, steel and cement manufacturers and fuel producers

The Rice Alliance Clean Energy Accelerator has supported 55 ventures since it was founded in 2021, collectively raising over $250 million in funding, according to the university. See last year's cohort here.