A handful of startups will be selected for the third year of the ACCEL program put on by Greentown Labs and Browning the Green Space. Photo via greentownlabs.com
For the third year, Greentown Labs and Browning the Green Space have opened applications for ACCEL, a climatetech accelerator designed to bolster BIPOC-led companies.
The program, which is a year-long commitment providing opportunities across funding, networking connections, resources, and more, has applications open until January 7. Each selected company will receive non-dilutive grant funding up to $25,000, trainings from VentureWell, a desk and membership at Greentown Houston or Boston locations, a BGS membership, and more.
A handful of startups will be selected for the program, which is looking for companies at the two to four Technology Readiness Level (TRL) stage with a technology solution across agriculture, buildings, electricity, manufacturing, resiliency and adaptation, and transportation sectors.
“ACCEL has been amazing," Chidalu Onyenso, founder of Cambridge, Massachusetts-based EarthBond, a member of the 2022 cohort, writes on the website. "I’ve really enjoyed the membership and programming. I think it’s fantastic—if I met another Black or Brown founder focused on climatetech, I’d tell them to apply to this program, 100 percent.”
"These BIPOC-led startups are developing climate technologies that will lead us to a more equitable and sustainable future," MassCEC CEO Dr. Emily Reichert, the former CEO of Greentown, said of the second cohort in a news release. "We want ALL climatetech innovators and entrepreneurs to thrive here in Massachusetts. We are proud to support the ACCEL accelerator, created and led by Greentown Labs and Browning the Green Space. The ACCEL program is helping us build a more diverse innovation ecosystem by breaking down barriers and expanding opportunities."
Interested and qualifying companies can apply online.
The seven selected startups will have year-long curated curriculum, incubation at Greentown's two locations, a non-dilutive $25,000 grant, and access to mentors, corporates, and more from both Greentown and BGS's networks. Photo via browningthegreenspace.org
Two organizations have named the seven startup participants for their accelerator that works to advance BIPOC-led startups in the climatetech space.
Greentown Labs and Browning the Green Space named the newest accelerator for the Advancing Climatetech and Clean Energy Leaders Program, or ACCEL. The seven selected startups will have year-long curated curriculum, incubation at Greentown's two locations, a non-dilutive $25,000 grant, and access to mentors, corporates, and more from both Greentown and BGS's networks.
"Building on the momentum and success of our inaugural year, Greentown Labs is proud to welcome this incredible cohort of BIPOC-led startups to Year 2 of ACCEL," Greentown Labs CEO and President Kevin Knobloch says in a news release. "These founders and their teams are developing a dynamic array of much-needed climatetech solutions, and we're privileged to support them on their startup journeys as they advance their technologies and grow their teams."
The 2024 cohort includes:
AtmoSpark Technologies, based in Houston, is an atmospheric water generation company with a patented electro-condensation technology, which has a lower energy footprint than that of current water-generation methods.
Cambridge, Massachusetts-based Aquasaic is harnessing biology to clean water for planetary and human health.
Houston-based Axis Sky Renewablescreates innovative wind solutions, specializing in vertical-axis wind turbines that are less expensive to produce, deploy, and maintain than traditional wind turbines.
Carbon Negative Solutions, from Rock Hill, New York, is creating smart-city-ready, carbon-negative concrete products.
NYC-based Cellsense develops interactive bio-embellishments that create new possibilities for designers while eliminating microplastics and replacing fossil-fuel-based material at scale.
EcoForge, headquartered in Providence, Rhode Island, is a building-material technology company developing affordable, high-performance building materials from local agricultural residues, replacing energy-intensive, fossil-based materials.
Boston-based Sankofa Dynamics creates low-cost, eco-friendly solutions for water, air, and energy problems.
"These BIPOC-led startups are developing climate technologies that will lead us to a more equitable and sustainable future," MassCEC CEO Dr. Emily Reichert, the former CEO of Greentown, says in the release. "We want ALL climatetech innovators and entrepreneurs to thrive here in Massachusetts. We are proud to support the ACCEL accelerator, created and led by Greentown Labs and Browning the Green Space. The ACCEL program is helping us build a more diverse innovation ecosystem by breaking down barriers and expanding opportunities."
"Our second year of ACCEL brings together an inspirational and diverse cohort of seven BIPOC-led startups developing tech to accelerate the distribution of climate solutions that address community needs," Browning the Green Space President and Executive Director Kerry Bowie adds. "We are thrilled to continue to strengthen our partnership with Greentown Labs and VentureWell and build on the learnings from the pilot cohort to provide critical support infrastructure for entrepreneurs of color."
The ACCEL program kicks off at an event on March 6 at Greentown's Boston location.
ACCEL has opened applications for next year. Photo via Getty Images
Calling all cleantech startups founded by innovators of color — an inclusive accelerator program is now accepting applications.
Advancing Climatetech and Clean Energy Leaders Program, or ACCEL, has opened applications for it's second cohort. The program — from Greentown Labs and Browning the Green Space — provides access to funding, networking connections, incubation space, mentorship, resources, and opportunities for energy tech founders of color for a year.
“ACCEL is one of the most impactful, meaningful programs we’ve run to date,” Greentown Labs CEO and President Kevin Knobloch says in a news release. “We are eager to expand upon the great success and momentum of year one, and to welcome another incredible cohort of BIPOC-led startups that are developing much-needed climatetech solutions. We’re equally committed to helping these companies accelerate and deploy their solutions, while also helping to build a more diverse, inclusive climatetech workforce—ACCEL sits at the nexus of those two critical efforts.”
“The ACCEL Program directly aligns with our mission to ensure that climatetech jobs and wealth creation opportunities are available to all residents of the Commonwealth,” Emily Reichert, CEO at MassCEC and former CEO at Greentown, says in the release. “We are excited to see the second round of this important program, with our Equity Workforce Fund support fostering a partnership between Greentown Labs and Browning the Green Space aimed at accelerating the growth of minority and women business enterprises in Massachusetts.”
ACCEL, which doles out $25,000 in non-dilutive grant funding to each participant, is also supported by Boston-based Barr Foundation and provides programming from VentureWell, a nonprofit with expertise in climatetech.
“Through our partnership with Greentown and VentureWell, we are able to put our respective strengths together to create an ambitious program to bolster founders of color in climatetech and propel innovations that benefit communities most impacted by climate change,” Kerry Bowie, executive director and president of Browning the Green Space, says in the release. “Opening applications for Year 2 of ACCEL is an important milestone in strengthening critical support for traditionally excluded entrepreneurs in our communities.”
Applications for ACCEL are open until January 5, 2024. While entrepreneurs from anywhere can apply, preference will be given to applicants in Greater Boston and Greater Houston, where Greentown’s incubators are located.
Houston maintained its No. 3 status this year among U.S. metro areas with the most Fortune 500 headquarters. Fortune magazine tallied 26 Fortune 500 headquarters in the Houston area, behind only the New York City area (62) and the Chicago area (30).
Last year, 23 Houston-area companies landed on the Fortune 500 list. Fortune bases the list on revenue that a public or private company earns during its 2024 budget year.
On the Fortune 500 list for 2025, Spring-based ExxonMobil remained the highest-ranked company based in the Houston area as well as in Texas, sitting at No. 8 nationally. That’s down one spot from its No. 7 perch on the 2024 list. During its 2024 budget year, ExxonMobil reported revenue of $349.6 billion, up from $344.6 billion the previous year.
Here are the rankings and 2024 revenue for the 25 other Houston-area companies that made this year’s Fortune 500:
Nationally, the top five Fortune 500 companies are:
Walmart
Amazon
UnitedHealth Group
Apple
CVS Health
“The Fortune 500 is a literal roadmap to the rise and fall of markets, a reliable playbook of the world's most important regions, services, and products, and an indispensable roster of those companies' dynamic leaders,” Anastasia Nyrkovskaya, CEO of Fortune Media, said in a news release.
Among the states, Texas ranks second for the number of Fortune 500 headquarters (54), preceded by California (58) and followed by New York (53).
Three Houston companies claimed spots on LexisNexis's 10 Most Innovative Startups in Texas report, with two working in the geothermal energy space.
Sage Geosystems claimed the No. 3 spot on the list, and Fervo Energy followed closely behind at No. 5. Fintech unicorn HighRadius rounded out the list of Houston companies at No. 8.
LexisNexis Intellectual Property Solutions compiled the report. It was based on each company's Patent Asset Index, a proprietary metric from LexisNexis that identifies the strength and value of each company’s patent assets based on factors such as patent quality, geographic scope and size of the portfolio.
Houston tied with Austin, each with three companies represented on the list. Caris Life Sciences, a biotechnology company based in Dallas, claimed the top spot with a Patent Asset Index more than 5 times that of its next competitor, Apptronik, an Austin-based AI-powered humanoid robotics company.
“Texas has always been fertile ground for bold entrepreneurs, and these innovative startups carry that tradition forward with strong businesses based on outstanding patent assets,” Marco Richter, senior director of IP analytics and strategy for LexisNexis Intellectual Property Solutions, said in a release. “These companies have proven their innovation by creating the most valuable patent portfolios in a state that’s known for game-changing inventions and cutting-edge technologies.We are pleased to recognize Texas’ most innovative startups for turning their ideas into patented innovations and look forward to watching them scale, disrupt, and thrive on the foundation they’ve laid today.”
This year's list reflects a range in location and industry. Here's the full list of LexisNexis' 10 Most Innovative Startups in Texas, ranked by patent portfolios.
Fervo Energy fully contracted its flagship 500 MW geothermal development, Cape Station, this spring. Cape Station is currently one of the world’s largest enhanced geothermal systems (EGS) developments, and the station will begin to deliver electricity to the grid in 2026. The company was recently named North American Company of the Year by research and consulting firm Cleantech Group and came in at No. 6 on Time magazine and Statista’s list of America’s Top GreenTech Companies of 2025. It's now considered a unicorn, meaning its valuation as a private company has surpassed $1 billion.
Meanwhile, HighRadius announced earlier this year that it plans to release a fully autonomous finance platform for the "office of the CFO" by 2027. The company reached unicorn status in 2020.
The climate conversation is evolving — fast. It’s no longer just about emissions targets and net-zero commitments. It’s about capital, infrastructure, and execution at industrial scale.
That’s exactly where Yao Huang operates. A seasoned tech entrepreneur turned climate investor, Yao brings sharp clarity to one of the biggest challenges in climate innovation: how do we fund and scale technologies that remove carbon without relying on goodwill or government subsidies?
In this episode of the Energy Tech Startups Podcast, Yao sits down with hosts Jason Ethier and Nada Ahmed for a wide-ranging conversation that redefines how we think about decarbonization. From algae-based photobioreactors that capture CO₂ at the smokestack, to financing models that mirror real estate and infrastructure—not venture capital—Yao lays out a case for why the climate fight will be won or lost on spreadsheets, not slogans.
Her message is as bold as it is practical: this isn’t about saving the planet for the sake of it. It’s about building profitable, resilient systems that scale. And Houston, with its industrial base and project finance expertise, is exactly the place to do it.
The 40-Gigaton Challenge—and a Pandemic Pivot
Yao’s entry into climate wasn’t part of a long-term plan. It was sparked by a quiet moment during the pandemic—and a book.
Reading How to Avoid a Climate Disaster by Bill Gates, she came to two uncomfortable realizations:
The people in power don’t actually have this figured out, and
She would be alive to suffer the consequences.
That insight jolted her out of the traditional tech world and into climate action. She studied at Stanford, surrounded herself with mentors, and began diving into early-stage climate deals. But she quickly realized that most of the solutions she was seeing were still years away from commercialization.
So she narrowed her focus: no R&D moonshots, no science experiments—just deployable solutions that could scale now.
Carbon Optimum: Where Algae Meets Infrastructure
That’s how she found Carbon Optimum, a company using algae photobioreactors to remove CO₂ directly from industrial emissions. Their approach is both elegant and economic:
Install algae reactors next to major emitters like coal and cement plants.
Feed the algae with flue gas, allowing it to absorb CO₂ in a controlled system.
Harvest the algae and convert it into valuable commodities like bio-oils, fertilizer, and food ingredients.
It’s a nature-based solution, enhanced by engineering. One acre of tanks can capture emissions and generate profit—without subsidies.
“This is one of the few solutions I’ve seen that can scale profitably and quickly,” Yao says. “And we’re not inventing anything new—we’re just doing it better.”
The Real Problem? It’s Capital, Not Carbon
As an investor, Yao is blunt: most climate startups are misaligned with the capital markets.
They’re following a tech startup playbook—built for SaaS, not steel. But building climate infrastructure requires a completely different approach: project finance, blended capital, debt structures, carbon credit integration, and regulatory incentives.
“Climate tech is more like real estate or healthcare than software,” Yao explains. “You don’t raise six rounds of venture. You build a stack—grants, equity, debt, tax credits—and you structure your project like infrastructure.”
It’s not just theory. It’s exactly how Carbon Optimum is expanding—through partnerships, offtake agreements, and real-world deployments. And it’s why she believes many climate startups fail: they don’t speak the language of finance.
Houston’s Role in the Climate Capital Stack
For Yao, Houston isn’t just a backdrop—it’s a strategic asset.
The city’s deep bench of project finance professionals, commodity traders, lawyers, and infrastructure veterans makes it uniquely positioned to lead the deployment phase of climate solutions.
“We’ve been calling it the wrong thing,” she says. “This isn’t just about climate—it’s an energy transition. And Houston knows how to build energy infrastructure at scale.”
Still, she notes, the ecosystem needs to evolve. Less education, more execution. Fewer workshops, more closers.
“Houston could be the epicenter of this movement—if we activate the right people and get the right projects over the line.”
From Carbon Capture to Circular Economies
The potential applications of Carbon Optimum’s algae platform go beyond carbon capture. Because the output—algae biomass—can be converted into:
Renewable oil
High-efficiency fertilizers (critical in today’s geopolitically fragile supply chains)
Food ingredients rich in protein and nutrients
Even biochar, a highly stable form of carbon sequestration
It’s scalable, modular, and location-agnostic. In island nations, Yao notes, these systems can offer energy independence by turning waste CO₂ into local energy and fertilizer—without needing to import fuels or food.
“It’s not just emissions reduction. It’s economic sovereignty through circular systems.”
Doing, Not Just Talking
One of Yao’s key takeaways for founders? Don’t waste time. Climate startups don’t have the luxury of trial-and-error cycles stretched over years.
“Founders need to get real about what it takes to scale: talent, capital, storytelling, partnerships. If you’re not ready to do that, maybe you should be a CSO, not a CEO.”
She also points out that founders don’t need to hire everyone—they need to tap the right networks. And in cities like Houston, those networks exist—if you know how to motivate them.
“It takes a different kind of leadership. You’re not just raising money—you’re moving people.”
Why This Episode Matters
This conversation is for anyone who’s serious about scaling real solutions to the climate crisis. Whether you’re a founder navigating capital markets, an investor seeking return and impact, or a policymaker designing the frameworks — Yao Huang offers a grounded, urgent, and actionable perspective.
It’s not about hope. It’s about execution.
Listen to the full episode of the Energy Tech Startups Podcast with Yao Huang:
-- Hosted by Jason Ethier and Nada Ahmed, the Digital Wildcatters’ podcast, Energy Tech Startups, delves into Houston's pivotal role in the energy transition, spotlighting entrepreneurs and industry leaders shaping a low-carbon future.