seeing green

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

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

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.

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A View From HETI

This year's finalists range from a lower-emission steel producer to a diagnostics platform developer working to support batteries used in data centers. Photo courtesy Hertha Metals

Houston is home to a growing number of startups reshaping what it means to be called the "Energy Capital of the World."

As part of the 2026 Houston Innovation Awards, our Energy Transition Business category honors those innovative startups that are providing solutions within renewables, climatetech, clean energy, alternative materials, circular economy and more.

Five clean energy startups have been named finalists for the 2026 award. The finalists, selected by our esteemed panel of judges, range from a lower-emission steel producer to a diagnostics platform developer working to support batteries used in data centers.

Read more about these innovative businesses, their initiatives, and their inspirational founders below. The 2026 winners will be announced on InnovationMap.com in mid-November.

Capwell Services

Methane capture company Capwell Services works to eliminate vented oil and gas emissions economically for operators. According to the company, methane emissions are vented from most oil and gas facilities due to safety protocols, and operators are not able to capture the gas cost-effectively, leading operators to emit more than 14 million metric tons of methane per year in the U.S. and Canada. Founded in 2022, Capwell specializes in low and intermittent flow vents for methane capture.

The company began as a University of Pennsylvania senior design project led by CEO Andrew Lane. It has since participated in programs with Greentown Labs, the Rice Clean Energy Accelerator and the Creative Destruction Lab Energy Cohort at Texas A&M University. The company moved to Houston in 2023 and raised a pre-seed round. It deployed two commercial units this year, according to its application.

FlowCellutions

Energytech startup FlowCellutions is developing a chemistry-agnostic diagnostics platform for flow and metal-air batteries supporting data centers and critical infrastructure. The platform is designed to help reduce operating costs, prevent failures and costly downtime, and extend battery lifetime from approximately seven years to more than 30 years. It has deployed four paid pilots and plans to take insights from the programs to develop its next-gen sensor platform technology.

CEO Becca Segel founded the company in 2022. It is a member of Greentown Labs, and Segel was a 2025 Activate Fellow. The company has raised over $2 million in non-dilutive funding and received a $1.5 million NSF SBIR Fast-Track award earlier this year.

Hertha Metals

Hertha Metals produces lower-cost, lower-emission steel and high-purity iron. The company has developed a single-step process that uses natural gas as a direct reductant instead of metallurgical coal, which cuts production costs by more than 25 percent and emissions by up to 50 percent, according to the company. The same process produces high-purity iron needed for high-purity steels and rare earth magnets. The company says it aims to "re-industrialize America’s production of critical materials."

Hertha Metals was founded by CEO Laureen Meroueh in 2022 and emerged from stealth last year with more than $17 million in venture capital funding. The company closed a $133.65 million Series A this month and also broke ground on its $100M high-purity iron factory known as Chalyx in Conroe.

Mars Materials

Clean chemical manufacturing business Mars Materials is working to convert captured carbon into resources, such as carbon fiber and wastewater treatment chemicals. The company develops and produces its drop-in chemical products in Houston and uses an in-licensed process for the National Renewable Energy Lab to produce acrylonitrile, which is used to produce plastics, synthetic fibers, and rubbers.

Founded in 2019 by CEO Aaron Fitzgerald, CTO Kristian Gubsch, and vice president of operations Trey Sheridan, the company has secured over $7.2M in financing and is backed by Bill Gates’ Breakthrough Energy, Shell, Black & Veatch, and other organizations. It won in the Minority-founded Business Category in last year's Houston Innovation Awards.

Solidec

Chemical manufacturing company Solidec has developed autonomous generators that extract molecules from water and air and convert them into pure chemicals and fuels that are free of carbon emissions on-site, eliminating the need for transport, storage, and permitting. The company was founded around innovations developed by Rice University associate professor Haotian Wang.

The company was selected for the Chevron Technology Ventures’ Catalyst Program, Greentown Labs, NSF I-Corps and was part of the first cohort of the Activate Houston program. It won first place at the 2024 startup pitch competition at CERAWeek. Solidec was founded in 2023 by Wang, who serves as an advisor, CEO Ryan DuChanois, and CTO Yang Xia. It closed a $2.5 million seed round in 2025.

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