According to a new report, Houston is one of the top cities for funding for sustainability companies. Photo via Getty Images

From a financial standpoint, Houston appears to be a sustainable environment for sustainability-focused startups.

An analysis by PromoLeaf, a retailer of sustainable promotional products, that came out at the end of last year ranks Houston fourth among U.S. cities for the average funding raised by locally based startups in the sustainability sector, according to Crunchbase data.

Per the report, the Bayou City attracts $150.7 million in sustainability funding for startups. Ahead of Houston are Salt Lake City with $204.5 million; Santa Monica, California, with $154.3 million; and Fremont, California, with $153.4 million.

PromoLeaf’s analysis features cities where at least 20 companies are focused on sustainability.

The analysis indicates Houston has 20.6 sustainability startups per 100,000 residents. Ranking first in that regard is Boulder, Colorado (115 per 100,000 residents).

While Houston trails Boulder by a long distance, it fares well among the Texas cities in the analysis:

  1. Austin, 26.2 sustainability startups per 100,000 residents
  2. Houston, 20.6 sustainability startups per 100,000 residents
  3. Midland, 18.8 sustainability startups per 100,000 residents
  4. Plano, 11.9 sustainability startups per 100,000 residents
  5. Dallas, 11 sustainability startups per 100,000 residents
  6. Fort Worth, 5.3 sustainability startups per 100,000 residents
  7. San Antonio, 5.2 sustainability startups per 100,000 residents

PromoLeaf says more than 21,600 sustainability startups operate in the U.S. They’re in the renewable energy, recycling and pollution control, environmental engineering, green consumer goods, and environmental consulting industries.

The analysis shows Houston has:

  • 13.7 renewable energy startups per 100,000 residents
  • 5.8 recycling and pollution control startups per 100,000 residents
  • 3.5 environmental engineering startups per 100,000 residents
  • 2.9 environmental consulting startups per 100,000 residents
  • 0.70 green consumer goods startups per 100,000 residents

According to the Greater Houston Partnership, renewable energy startups leading Houston’s energy transformation include Energy Transition Ventures, Fysikes Biosolutions, Ionada, Katz Water Technologies, Pressure Corp., and Renewell Energy.

“A dynamic business climate combined with growth in venture capital funding in Houston has created fertile ground for companies of all stages aiming to power our world through the global energy transition,” the partnership says. “As the Energy Capital of the World, Houston has become a hub for startups and venture capital firms investing in the region’s energy future.”

Outside the energy sector, Houston startups like Trendy Seconds also are making their mark in sustainability. The company runs an online marketplace where women can find preowned clothing or shop for new clothing from sustainable brands.

“Our ultimate goal is to make responsible consumption super easy,” Maria Burgos, founder of Trendy Seconds, told InnovationMap last year.

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This article originally ran on InnovationMap.

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40+ climatetech startups join Greentown, including a dozen from Houston

green team

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."

NRG makes latest partnership to grow virtual power plant

VPP partners

Houston-based NRG Energy recently announced a new long-term partnership with San Francisco-based Sunrun that aims to meet Texas’ surging energy demands and accelerate the adoption of home battery storage in Texas. The partnership also aligns with NRG’s goal of developing a 1-gigawatt virtual power plant by connecting thousands of decentralized energy sources by 2035.

Through the partnership, the companies will offer Texas residents home energy solutions that pair Sunrun’s solar-plus-storage systems with optimized rate plans and smart battery programming through Reliant, NRG’s retail electricity provider. As new customers enroll, their stored energy can be aggregated and dispatched to the ERCOT grid, according to a news release.

Additionally, Sunrun and NRG will work to create customer plans that aggregate and dispatch distributed power and provide electricity to Texas’ grid during peak periods.

“Texas is growing fast, and our electricity supply must keep pace,” Brad Bentley, executive vice president and president of NRG Consumer, said in the release. “By teaming up with Sunrun, we’re unlocking a new source of dispatchable, flexible energy while giving customers the opportunity to unlock value from their homes and contribute to a more resilient grid

Participating Reliant customers will be paid for sharing their stored solar energy through the partnership. Sunrun will be compensated for aggregating the stored capacity.

“This partnership demonstrates the scale and strength of Sunrun’s storage and solar distributed power plant assets,” Sunrun CEO Mary Powell added in the release. “We are delivering critical energy infrastructure that gives Texas families affordable, resilient power and builds a reliable, flexible power plant for the grid.”

In December, Reliant also teamed up with San Francisco tech company GoodLeap to bolster residential battery participation and accelerate the growth of NRG’s virtual power plant network in Texas.

In 2024, NRG partnered with California-based Renew Home to distribute hundreds of thousands of VPP-enabled smart thermostats by 2035 to help households manage and lower their energy costs. At the time, the company reported that its 1-gigawatt VPP would be able to provide energy to 200,000 homes during peak demand.