A team of Rice researchers, including Caroline Ajo-Franklin and Biki Bapi Kundu, has uncovered how certain bacteria breathe by generating electricity. Photo by Jeff Fitlow/Rice University.
New research from Rice University that merges biology with electrochemistry has uncovered new findings on how some bacteria generate electricity.
Led by Caroline Ajo-Franklin, a Rice professor of biosciences and the director of the Rice Synthetic Biology Institute, the team published its findings in the journal Cell in April. The report showed how some bacteria use compounds called naphthoquinones, rather than oxygen, to transfer electrons to external surfaces in a process known as extracellular respiration. In other words, the bacteria are exhale electricity as they breathe.
This process has been observed by scientists for years, but the Rice team's deeper understanding of its mechanism is a major breakthrough, with implications for the clean energy and industrial biotechnology sectors, according to the university.
“Our research not only solves a long-standing scientific mystery, but it also points to a new and potentially widespread survival strategy in nature,” Ajo-Franklin, said in a news release.
The Rice team worked with the University of California, San Diego's Palsson lab to simulate bacterial growth using advanced computer modeling. The simulations modeled oxygen-deprived environments that were rich in conductive surfaces, and found that bacteria could sustain themselves without oxygen. Next, they confirmed that the bacteria continued to grow and generate electricity when placed on conductive materials.
The team reports that the findings "lay the groundwork for future technologies that harness the unique capabilities" of these bacteria with "far-reaching practical implications." The team says the findings could lead to significant improvements in wastewater treatment and biomanufacturing. They could also allow for better bioelectronic sensors in oxygen-deprived environments, including deep-sea vents, the human gut and in deep space.
“Our work lays the foundation for harnessing carbon dioxide through renewable electricity, where bacteria function similarly to plants with sunlight in photosynthesis,” Ajo-Franklin added in the release. “It opens the door to building smarter, more sustainable technologies with biology at the core.”
Rice University's Menachem Elimelech and Yuanmiaoliang “Selina” Chen published a study in Nature Water on mimicking dialysis from the medical field to treat wastewater. Photo by Gustavo Raskosky/Rice University
By employing medical field technology dialysis, researchers at Rice University and the Guangdong University of Technology in China uncovered a new way to treat high-salinity organic wastewater.
In the medical field, dialysis uses a machine called a dialyzer to filter waste and excess fluid from the blood. In a study published in Nature Water, Rice’s team found that mimicking dialysis can separate salts from organic substances with minimal dilution of the wastewater, addressing some of the limitations of previous methods.
The researchers say this has the potential to lower costs, recover valuable resources across a range of industrial sectors and reduce environmental impacts.
“Traditional methods often demand a lot of energy and require repeated dilutions,” Yuanmiaoliang “Selina” Chen, a co-first author and postdoctoral associate in Elimelech’s lab at Rice, said in a news release. “Dialysis eliminates many of these pain points, reducing water consumption and operational overheads.”
Various industries generate high-salinity organic wastewater, including petrochemical, pharmaceutical and textile manufacturing. The wastewater’s high salt and organic content can present challenges for existing treatment processes. Biological and advanced oxidation treatments become less effective with higher salinity levels. Thermal methods are considered “energy intensive” and susceptible to corrosion.
Ultimately, the researchers found that dialysis effectively removed salt from water without requiring large amounts of fresh water. This process allows salts to move into the dialysate stream while keeping most organic compounds in the original solution. Because dialysis relies on diffusion instead of pressure, salts and organics cross the membrane at different speeds, making the separation method more efficient.
“Dialysis was astonishingly effective in separating the salts from the organics in our trials,” Menachem Elimelech, a corresponding author on the study and professor of civil and environmental engineering and chemical and biomolecular engineering at Rice, said in a news release. “It’s an exciting discovery with the potential to redefine how we handle some of our most intractable wastewater challenges.”
A new study on Mars is shining a light on the Earth's own climate mysteries. Image via UH.edu
Scientists at the University of Houston have found a new understanding of climate and weather on Mars.
The study, which was published in a new paper in AGU Advances and will be featured in AGU’s science magazine EOS, generated the first meridional profile of Mars’ radiant energy budget (REB). REB represents the balance or imbalance between absorbed solar energy and emitted thermal energy across latitudes. An energy surplus can lead to global warming, and a deficit results in global cooling, which helps provide insights to Earth's atmospheric processes too. The profile of Mars’ REB influences weather and climate patterns.
The study was led by Larry Guan, a graduate student in the Department of Physics at UH's College of Natural Sciences and Mathematics under the guidance of his advisors Professor Liming Li from the Department of Physics and Professor Xun Jiang from the Department of Earth and Atmospheric Sciences and other planetary scientists. UH graduate students Ellen Creecy and Xinyue Wang, renowned planetary scientists Germán Martínez, Ph.D. (Houston’s Lunar and Planetary Institute), Anthony Toigo, Ph.D. (Johns Hopkins University) and Mark Richardson, Ph.D. (Aeolis Research), and Prof. Agustín Sánchez-Lavega (Universidad del País, Vasco, Spain) and Prof. Yeon Joo Lee (Institute for Basic Science, South Korea) also assisted in the project.
The profile of Mars’ REB is based on long-term observations from orbiting spacecraft. It offers a detailed comparison of Mars’ REB to that of Earth, which has shown differences in the way each planet receives and radiates energy. Earth shows an energy surplus in the tropics and a deficit in the polar regions, while Mars exhibits opposite behavioral patterns.
The surplus is evident in Mars’ southern hemisphere during spring, which plays a role in driving the planet’s atmospheric circulation and triggering the most prominent feature of weather on the planet, global dust storms. The storms can envelop the entire planet, alter the distribution of energy, and provide a dynamic element that affects Mars’ weather patterns and climate.
The research team is currently examining long-term energy imbalances on Mars and how it influences the planet’s climate.
“The REB difference between the two planets is truly fascinating, so continued monitoring will deepen our understanding of Mars’ climate dynamics,” Li says in a news release.
The global-scale energy imbalance on Earth was recently discovered, and it contributes to global warming at a “magnitude comparable to that caused by increasing greenhouse gases,” according to the study. Mars has an environment that differs due to its thinner atmosphere and lack of anthropogenic effects.
“The work in establishing Mars’ first meridional radiant energy budget profile is noteworthy,” Guan adds. “Understanding Earth’s large-scale climate and atmospheric circulation relies heavily on REB profiles, so having one for Mars allows critical climatological comparisons and lays the groundwork for Martian meteorology.”
These five Houston-based energy transition research news articles trended this year on EnergyCapital. Photo via Getty Images
Editor's note: As the year comes to a close, EnergyCapital is looking back at the year's top stories in Houston energy transition. When it comes to the future of energy, Houston has tons of forward-thinking minds hard at work researching solutions to climate change and its impact on Earth. The following research-focused articles that stood out to readers this year — be sure to click through to read the full story.
Researchers Rahul Pandey, senior scientist with SRI and principal investigator (left), and Praveen Bollini, a University of Houston chemical engineering faculty, are key contributors to the microreactor project. Photo via uh.edu
A University of Houston-associated project was selected to receive $3.6 million from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy that aims to transform sustainable fuel production.
Nonprofit research institute SRI is leading the project “Printed Microreactor for Renewable Energy Enabled Fuel Production” or PRIME-Fuel, which will try to develop a modular microreactor technology that converts carbon dioxide into methanol using renewable energy sources with UH contributing research.
“Renewables-to-liquids fuel production has the potential to boost the utility of renewable energy all while helping to lay the groundwork for the Biden-Harris Administration’s goals of creating a clean energy economy,” U.S. Secretary of Energy Jennifer M. Granholm says in an ARPA-E news release. Continue reading.
Researchers from Rice University and the University of Texas have teamed up for semiconductor microsystem innovation. Photo courtesy of UT
A team led by the University of Texas at Austin and partnered with Rice University was awarded $840 million to develop “the next generation of high-performing semiconductor microsystems" for the U.S. Department of Defense.
The Defense Advanced Research Projects Agency (DARPA) selected UT’s Texas Institute for Electronics (TIE) semiconductor consortium to establish a national open access R&D and prototyping fabrication facility.
The facility hopes to enable the DOD to create higher performance, lower power, lightweight, and compact defense systems. The technology could apply to radar, satellite imaging, unmanned aerial vehicles, or other systems, and ultimately will assist with national security and global military leadership. As a member of DARPA’s Next Generation Microelectronics Manufacturing (NGMM) team, Rice’s contributions are key.
Executive vice president for research Ramamoorthy Ramesh and the Rice researchers will focus on technologies for improving computing efficiency. In a Rice press release, Ramesh notes the need to enhance “energy-efficient computing” which highlights Rice’s qualifications to contribute to the solution. Continue reading.
Led by Haotian Wang (left) and Feng-Yang Chen, the Rice University team published a study this month detailing how its reactor system sustainably converts waste into ammonia. Photo by Jeff Fitlow/Rice University
A team of Rice University engineers has developed a reactor design that can decarbonize ammonia production, produce clean water and potentially have applications in further research into other eco-friendly chemical processes.
Led by Rice associate professor Haotian Wang, the team published a study this month in the journal Nature Catalysis that details how the new reactor system sustainably and efficiently converts nitrates (common pollutants found in industrial wastewater and agricultural runoff) into ammonia, according to the university. The research was supported by Rice and the National Science Foundation.
“Our findings suggest a new, greener method of addressing both water pollution and ammonia production, which could influence how industries and communities handle these challenges,” Wang says in a statement. “If we want to decarbonize the grid and reach net-zero goals by 2050, there is an urgent need to develop alternative ways to produce ammonia sustainably.” Continue reading.
OpenSafe.AI, a new platform that utilizes AI, data, and hazard and resilience models to support storm response decision makers, has secured an NSF grant. Photo via Getty Images
Researchers from Rice University have secured a $1.5 million grant from the National Science Foundation to continue their work on improving safety and resiliency of coastal communities plagued by flooding and hazardous weather.
Together, the team is developing and hopes to deploy “Open-Source Situational Awareness Framework for Equitable Multi-Hazard Impact Sensing using Responsible AI,” or OpenSafe.AI, a new platform that utilizes AI, data, and hazard and resilience models "to provide timely, reliable and equitable insights to emergency response organizations and communities before, during and after tropical cyclones and coastal storm events," reads a news release from Rice. Continue reading.
For the first time, Texas's ERCOT grid will be connected to other states' grids thanks to funding from the Department of Energy. Photo via Getty Images
Thanks to recently announced funding, the power grid for the territory served by the Electric Reliability Council of Texas (ERCOT) will be connected to grids in other states.
Officials hope building a 320-mile transmission line that connects the ERCOT electric grid to electric grids in the Southeast will prevent power outages like the massive blackout that occurred in 2022 when a winter storm blasted Texas.
San Francisco-based Pattern Energy says its Southern Spirit project will cost more than $2.6 billion. Full-scale construction is supposed to get underway in 2028, and the project is set to go online in 2031. Continue reading.
ReVolt Battery Technology Corp. is based out of the University of Houston Innovation Center. Photo via revoltbatterytechnology.com
A Houston company that's electrifying public transportation secured a SBIR Phase 1 award from the Department of Transportation.
ReVolt Battery Technology Corp., software-as-a-service company based out of the University of Houston Innovation Center, received the award. The company did not disclose the monetary value of the funding, but indicated that the grant will support ReVolt's "research on reducing auxiliary power consumption in battery electric buses," according to a statement from the company.
"ReVolt stands out as one of only 23 small businesses across the United States to be selected in this highly competitive process, which focuses on creating innovative infrastructure for safe and secure transportation," reads the statement.
The company's software technology platform consists of charging infrastructure, electric vehicle scheduling, fleet digital twin, and greenhouse gas reduction and estimation.
The company was founded in 2021 by Jan Naidu and, according to Crunchbase, has raised $200,000 in pre-seed funding.
A Rice University team researching carbon nanotube synthesis has received $4.1 million funding from both Rice’s Carbon Hub and The Kavli Foundation. Photo by Gustavo Raskosky/Rice University
A Rice University-led team of scientists has been awarded a $4.1 million grant to optimize a synthesis process that could make carbon materials sustainable and affordable on a large scale.
Known as carbon nanotube (CNT) synthesis, the process has the ability to create hollow cylindrical nanoscale structures made from carbon atoms that are strong, lightweight and carry heat and electricity well. CNT synthesis evolved across multiple countries around the same time, according to Rice. But to scale up the process in a way that could create alternatives to materials dependent on heavy industry, Matteo Pasquali, the team's leader and the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, says collaboration will be required.
“We have to apply a collaborative mindset to solve this problem,” Pasquali says in a statement. “We believe that by bringing together a dedicated interdisciplinary community, this project will lead to improvements in reactor efficiency and help identify further gaps in instrumentation and modeling.”
The grant seeks to achieve that. The funds come from both Rice’s Carbon Hub, which contributed $2.2 million to the team, and The Kavli Foundation, which granted $1.9 million in the form of a Kavli Exploration Award in Nanoscience for Sustainability.
The Kavli Foundation supports research in astrophysics, nanoscience, neuroscience and theoretical physics. Winners of its Kavli Prize, which recognizes scientific breakthroughs, often go on to win the Nobel Prize.
“We are proud to partner with Rice University to support this important high-risk, high-reward research,” says Amy Bernard, director of life sciences at The Kavli Foundation, says in a statement.
Pasquali is the director and one of the creators of Rice's Carbon Hub, a collaborative group of corporations, researchers, universities and nonprofits focused on decarbonizing the economy. He says the grant will help the team develop tools to shed light on CNT formation and reaction zones.
“We are at a critical juncture in carbon research, and it is really important that we shed light on the physical and chemical processes that drive CNT synthesis,” Pasquali says. “Currently, reactors are black boxes, which prevents us from ramping up synthesis efficiency. We need to better understand the forces at play in CNT formation by developing new tools to shed light on the reaction zone and find ways to leverage it to our advantage.”
Boris Yakobson, the Karl F. Hasselmann Professor of Engineering and professor of materials science and nanoengineering at Rice, and Thomas Senftle, assistant professor of chemical and biomolecular engineering at Rice, are also involved in the project. Other collaborators hail from the UK, Italy, Korea, and Spain, as well as U.S. labs and universities, including Harvard, Stanford, MIT and others.
In October, a separate team of Rice researchers released a study on a new synthesis process with applications in developing commercially relevant solar cells.
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.
