Greentown accelerator in partnership with Shell wraps up with startup milestones met

that's a wrap

The cohort was selected from over 100 applications, and experts from Shell worked to support the cohort as they navigated the program. Photo via Greentown Labs

After six months of incubating with Shell through Greentown Labs, the 2023 Greentown Go Make startup cohort has completed with its recent showcase.

The six participating startups — Caravel Bio, Circularise, Corumat, Lydian, Maple Materials, and Universal Matter — were originally announced in October. The cohort was selected from over 100 applications, and experts from Shell worked to support the cohort as they navigated the program.

Universal Matter, headquartered in Burlington, Ontario, Canada, with a Houston office, is developing a proprietary flash Joule heating process that converts carbon waste into high-value and high-performance graphene materials to efficiently create sustainable, circular economies.

During the program, Universal Matter worked with Shell to identify eight potential collaboration areas across upstream carbon feedstocks, downstream end-use applications for the startup’s graphene, and more, according to a news release from Greentown.

“Go Make 2023 was run with exceptional efficiency to ensure that all startup members were able to gain maximum benefit from exchanges with the corporate partner,” says Universal Matter’s VP of Strategic Planning Peter van Ballegooie.

“The one-on-one exchanges were extremely useful to startups, as they facilitated the connections to the relevant business units within Shell that could potentially benefit from the novel technologies being developed," he continues. "Establishing the connectivity to the right discussion partners within those various business units was absolutely key to the successful outcome of the program.”

Greentown shared more about each of the company's progress throughout the program in a blog post.

Meet the six startups that will be working with Shell and Greentown Labs for the next six months. Photo via Greentown

Greentown Labs names 6 energy tech startups to Shell-backed accelerator

ready to go make

Greentown Labs has named the six participating climatetech startups for an accelerator for a global energy leader.

Shell and Greentown Labs announced the cohort for Greentown Go Make 2023 — a program designed to accelerate partnerships between startups and corporates to advance carbon utilization, storage, and traceability solutions. Shell, which invests in net-zero and carbon-removal technologies, is hoping to strategically align with startups within carbon utilization, storage, and traceability across the energy transition spectrum.

“At Greentown Labs we recognize and appreciate the role energy incumbents must play in the energy transition, and we’re eager to facilitate meaningful partnerships between these impressive startups and Shell—not only to advance these technologies but also to help Shell achieve its sustainability goals,” Kevin Knobloch, CEO and President of Greentown Labs, says in a news release. “We know carbon utilization, storage, and traceability will play a critical role in our collective efforts to reach net-zero, and we’re enthusiastic about the potential impact these companies can have in that work.”

The cohort, selected from 110 applications, is co-located at Greentown's Houston and Somerville, Massachusetts, locations and includes:

Portland-based Caravel Bio is developing a novel synthetic biology platform that uses microbial spores and enzymes to create catalysts that are long-lasting and can withstand extreme conditions and environments.
Circularise, which is based in the Netherlands, is developing a blockchain platform that provides digital product passports for end-to-end traceability and secure data exchange for industrial supply chains.
Corumat, based in Washington, converts organic waste into high-performance, insulating, greaseproof, and biodegradable packaging materials.
Cambridge, Massachusetts-headquartered Lydian develops a fully electrified reactor that can convert a variety of gaseous, non-fossil feedstocks into pure syngas with high efficiency.
Maple Materials from Richmond, California is developing a low-cost electrolysis process to split carbon dioxide into graphite and oxygen.
Ontario, Canada-founded Universal Matter develops a proprietary Flash Joule Heating process that converts carbon waste into high-value and high-performance graphene materials to efficiently create sustainable circular economies.

The program, which includes $15,000 in non-dilutive stipend funding for each company, will work closely with Shell and Greentown over six months via mentorship, networking opportunities, educational workshops, and partnership-focused programming to support collaboration. Go Make 2023 concludes with a showcase event on March 27 at Greentown Labs’ Houston location.

This week, Shell announced another accelerator cohort it's participating in. The Shell GameChanger Accelerator, a partnership with the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), named four West Coast climatetech companies: DTE Materials, Hexas Biomass, Invizyne Technologies, and ZILA BioWorks. The program provides early-stage cleantech startups with access to experts and facilities to reduce technology development risk and accelerate commercialization of new cleaner technologies.

“Tackling the climate challenge requires multifaceted solutions. At Shell, we believe technology that removes carbon dioxide from the atmosphere will be essential for lowering emissions from energy and chemical products,” Yesim Jonsson, Shell’s GCxN program manager, says in a statement. “The companies in GCxN's sixth cohort embody these objectives and have the potential to usher in a more sustainable future.”

Ad Placement 300x100

Ad Placement 300x600

CultureMap Emails are Awesome

Property Showcase

Houston geothermal company raises $97M Series B

fresh funding

Houston-based geothermal energy startup Sage Geosystems has closed its Series B fundraising round and plans to use the money to launch its first commercial next-generation geothermal power generation facility.

Ormat Technologies and Carbon Direct Capital co-led the $97 million round, according to a press release from Sage. Existing investors Exa, Nabors, alfa8, Arch Meredith, Abilene Partners, Cubit Capital and Ignis H2 Energy also participated, as well as new investors SiteGround Capital and The UC Berkeley Foundation’s Climate Solutions Fund.

The new geothermal power generation facility will be located at one of Ormat Technologies' existing power plants. The Nevada-based company has geothermal power projects in the U.S. and numerous other countries around the world. The facility will use Sage’s proprietary pressure geothermal technology, which extracts geothermal heat energy from hot dry rock, an abundant geothermal resource.

“Pressure geothermal is designed to be commercial, scalable and deployable almost anywhere,” Cindy Taff, CEO of Sage Geosystems, said in the news release. “This Series B allows us to prove that at commercial scale, reflecting strong conviction from partners who understand both the urgency of energy demand and the criticality of firm power.”

Sage reports that partnering with the Ormat facility will allow it to market and scale up its pressure geothermal technology at a faster rate.

“This investment builds on the strong foundation we’ve established through our commercial agreement and reinforces Ormat’s commitment to accelerating geothermal development,” Doron Blachar, CEO of Ormat Technologies, added in the release. “Sage’s technical expertise and innovative approach are well aligned with Ormat’s strategy to move faster from concept to commercialization. We’re pleased to take this natural next step in a partnership we believe strongly in.”

In 2024, Sage agreed to deliver up to 150 megawatts of new geothermal baseload power to Meta, the parent company of Facebook. At the time, the companies reported that the project's first phase would aim to be operating in 2027.

The company also raised a $17 million Series A, led by Chesapeake Energy Corp., in 2024.

Houston expert discusses the clean energy founder's paradox

Guest Column

Everyone tells you to move fast and break things. In clean energy, moving fast without structural integrity means breaking the only planet we’ve got. This is the founder's paradox: you are building a company in an industry where the stakes are existential, the timelines are glacial, and the capital requires patience.

The myth of the lone genius in a garage doesn’t really apply here. Clean energy startups aren’t just fighting competitors. They are fighting physics, policy, and decades of existing infrastructure. This isn’t an app. You’re building something physical that has to work in the real world. It has to be cheaper, more reliable, and clearly better than fossil fuels. Being “green” alone isn’t enough. Scale is what matters.

Your biggest risks aren’t competitors. They’re interconnection delays, permitting timelines, supply chain fragility, and whether your first customer is willing to underwrite something that hasn’t been done before.

That reality creates a brutal filter. Successful founders in this space need deep technical knowledge and the ability to execute. You need to understand engineering, navigate regulation, and think in terms of markets and risk. You’re not just selling a product. You’re selling a future where your solution becomes the obvious choice. That means connecting short-term financial returns with long-term system change.

The capital is there, but it’s smarter and more demanding. Investors today have PhDs in electrochemistry and grid dynamics. They’ve been burned by promises of miracle materials that never left the lab. They don't fund visions; they fund pathways to impact that can scale and make financial sense. Your roadmap must show not just a brilliant invention, but a clear, believable plan to drive costs down over time.

Capital in this sector isn’t impressed by ambition alone. It wants evidence that risk is being retired in the right order — even if that means slower growth early.

Here’s the upside. The difficulty of clean energy is also its strength. If you succeed, your advantage isn’t just in software or branding. It’s in hardware, supply chains, approvals, and years of hard work that others can’t easily copy. Your real competitors aren’t other startups. They’re inertia and the existing system. Winning here isn’t zero-sum. When one solution scales, it helps the entire market grow.

So, to the founder in the lab, or running field tests at a remote site: your pace will feel slow. The validation cycles are long. But you are building in the physical world. When you succeed, you don’t have an exit. You have a foundation. You don't just have customers; you have converts. And the product you ship doesn't just generate revenue; it creates a legacy.

If your timelines feel uncomfortable compared to software, that’s because you’re operating inside a system designed to resist change. And let’s not forget you are building actual physical products that interact with a complex world. Times are tough. Don’t give up. We need you.

---

Nada Ahmed is the founding partner at Houston-based Energy Tech Nexus.

Houston maritime startup raises $43M to electrify cargo vessels

A Houston-based maritime technology company that is working to reduce emissions in the cargo and shipping industry has raised VC funding and opened a new Houston headquarters.

Fleetzero announced that it closed a $43 million Series A financing round this month led by Obvious Ventures with participation from Maersk Growth, Breakthrough Energy Ventures, 8090 Industries, Y Combinator, Shorewind, Benson Capital and others. The funding will go toward expanding manufacturing of its Leviathan hybrid and electric marine propulsion system, according to a news release.

The technology is optimized for high-energy and zero-emission operation of large vessels. It uses EV technology but is built for maritime environments and can be used on new or existing ships with hybrid or all-electric functions, according to Fleetzero's website. The propulsion system was retrofitted and tested on Fleetzero’s test ship, the Pacific Joule, and has been deployed globally on commercial vessels.

Fleetzero is also developing unmanned cargo vessel technology.

"Fleetzero is making robotic ships a reality today. The team is moving us from dirty, dangerous, and expensive to clean, safe, and cost-effective. It's like watching the future today," Andrew Beebe, managing director at Obvious Ventures, said in the news release. "We backed the team because they are mariners and engineers, know the industry deeply, and are scaling with real ships and customers, not just renderings."

Fleetzero also announced that it has opened a new manufacturing and research and development facility, which will serve as the company's new headquarters. The facility features a marine robotics and autonomy lab, a marine propulsion R&D center and a production line with a capacity of 300 megawatt-hours per year. The company reports that it plans to increase production to three gigawatt-hours per year over the next five years.

"Houston has the people who know how to build and operate big hardware–ships, rigs, refineries and power systems," Mike Carter, co-founder and COO of Fleetzero, added in the release. "We're pairing that industrial DNA with modern batteries, autonomy, and software to bring back shipbuilding to the U.S."

View All Listings

ENERGYCAPITALHTX EMAILS ARE AWESOME