The Rice Alliance Clean Energy Accelerator has named its fifth cohort. Photo via the Ion

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.

Houston Energy and Climate Startup Week is coming back for a second year. Photo via GHP

Houston Energy and Climate Startup Week announces 2025 dates, key events

comeback tour

Six local organizations focused on the energy transition have teamed up to bring back Houston Energy and Climate Startup Week.

The second annual event will take place Sept. 15-19, according to an announcement. The Ion District will host many of the week's events.

Houston Energy and Climate Startup Week was founded in 2024 by Rice Alliance for Technology and Entrepreneurship, Halliburton Labs, Greentown Labs, Houston Energy Transition Initiative (HETI), Digital Wildcatters and Activate.

“Houston Energy and Climate Startup Week was created to answer a fundamental question: Can we achieve more by working together than we can alone?” Jane Stricker, senior vice president at the Greater Houston Partnership and executive director of HETI, said in the release.

So far, events for the 2025 Houston Energy and Climate Startup Week include an introduction to climatetech accelerator Activate's latest cohort, the Rice Alliance Energy Tech Venture Forum, a showcase from Greentown Labs' ACCEL cohort, and Halliburton Labs Pitch Day.

Houston organizations New Climate Ventures and Digital Wildcatters, along with Global Corporate Venturing, are slated to offer programming again in 2025. And new partners, Avatar Innovations and Decarbonization Partners, are slated to introduce events. Find a full schedule here.

Other organizations can begin entering calendar submissions starting in May, according to the release.

Last year, Houston Energy and Climate Startup Week welcomed more than 2,000 attendees, investors and industry leaders to more than 30 events. It featured more than 100 speakers and showcased more than 125 startups.

"In 2024, we set out to build something with lasting impact—rooted in the ingenuity of Houston’s technologists and founders. Thanks to a collaborative effort across industry, academia, and startups, we’ve only just begun to showcase Houston’s strengths and invite others to be part of this movement," Stricker added in the release. "We can’t wait to see the city rise to the occasion again in 2025.”

The week, which will be hosted at the Ion and around Houston, will gather investors, industry leaders, and startups from across the energy industry to showcase Houston's growing sustainability community. Photo via the Ion

Houston to host inaugural climate tech and energy-focused week

coming soon

Three organizations are teaming up to put on a week of programming and events focused on energy and climate startups.

Greentown Labs, Halliburton Labs, and the Rice Alliance for Technology and Entrepreneurship have announced Houston Energy and Climate Startup Week 2024 taking place September 9 to 13.

“These organizations will execute events that will serve as a launching pad for an Energy and Climate Startup Week in Houston, showcasing the city as a national hub for the energy future,” Brad Burke, executive director of the Rice Alliance, says in the release. “We welcome the community to bring other energy and climate events to the week, which we’ll cross-promote as the dates approach.”

The week will assemble investors, industry leaders, and startups from across the energy industry and from around the world to showcase Houston's growing sustainable, low-carbon energy future.

The initiative is in collaboration with the Houston Energy Transition Initiative, or HETI, an initiative of the Greater Houston Partnership, as well as Activate, Digital Wildcatters, Renewable Energy Alliance Houston, and TEX-E.

“As the energy capital and one of the most diverse cities in the world, Houston stands as a center point for these solutions. The region is welcoming, diverse and has the know-how to play a critical role in building an energy abundant, low-carbon future," Jane Stricker, executive director of HETI and senior vice president at GHP, says in the release. "We welcome all who want to be part of the solution to join for this exciting, inaugural week of events.”

Attendees can expect tech and startup showcases, panels, pitches, discussions, and networking events to be hosted across Houston and at the Ion, Rice's innovation hub in Midtown. More details on the events will be added to the Ion's website as they become available.

“We look forward to the opportunity to highlight talented founders and connect them with investors, industry practitioners and university resources to help accelerate energy innovation,” Dale Winger, managing director of Halliburton Labs, says in the release. “The collaboration to launch Energy and Climate Startup Week reflects how Houston works together to scale solutions."

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This article originally ran on InnovationMap.

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Houston earns No. 3 spot among cities with most Fortune 500 headquarters

biggest companies

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:

  • No. 16 Chevron, $202.8 billion
  • No. 28 Phillips 66, $145.5 billion
  • No. 56 Sysco, $78.8 billion
  • No. 75 Conoco Phillips, $56.9 million
  • No. 78 Enterprise Products Partners, $56.2 billion
  • No. 92 Plains GP Holdings, $50 billion
  • No. 143 Hewlett-Packard Enterprise, $30.1 billion
  • No. 153 NRG Energy, $28.1 billion
  • No. 155 Baker Hughes, $27.8 billion
  • No. 159 Occidental Petroleum, $26.9 billion
  • No. 183 EOG Resources, $23.7 billion
  • No. 184 Quanta Services, $23.7 billion
  • No. 194 Halliburton, $23 billion
  • No. 197 Waste Management, $22.1 billion
  • No. 214 Group 1 Automotive, $19.9 billion
  • No. 224 Corebridge Financial, $18.8 billion
  • No. 256 Targa Resources, $16.4 billion
  • No. 275 Cheniere Energy, $15.7 billion
  • No. 289 Kinder Morgan, $15.1 billion
  • No. 345 Westlake Corp., $12.1 billion
  • No. 422 APA, $9.7 billion
  • No. 443 NOV, $8.9 billion
  • No. 450 CenterPoint Energy, $8.6 billion
  • No. 474 Par Pacific Holdings, $8 billion
  • No. 480 KBR Inc., $7.7 billion

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).

3 Houston energy companies rank among most innovative startups in Texas

report card

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.

  1. Caris (Dallas)
  2. Apptronik (Austin)
  3. Sage Geosystems (Houston)
  4. HiddenLayer (Austin)
  5. Fervo Energy (Houston)
  6. Plus One Robotics (San Antonio)
  7. Diligent Robotics (Austin)
  8. HighRadius (Houston)
  9. LTK (Dallas)
  10. Eagle Eye Networks (Austin)

Sage Geosystems has partnered on major geothermal projects with the United States Department of Defense's Defense Innovation Unit, the U.S. Air Force and Meta Platforms. Sage's 3-megawatt commercial EarthStore geothermal energy storage facility in Christine, Texas, was expected to be completed by the end of last year.

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.

Tech entrepreneur turned climate investor is on a mission to monetize carbon removal

now streaming

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:

  1. The people in power don’t actually have this figured out, and
  2. 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:


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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.