Here are the 100 startups selected to participate in this year's Rice Alliance Energy Tech Venture Forum. Photo by Natalie Harms

The Rice Alliance for Technology and Entrepreneurship has named the 100 energy technology ventures that will convene next month at the 22nd annual Rice Alliance Energy Tech Venture Forum, as part of the second annual Houston Energy and Climate Startup Week.

Half of the startups, which hail from nine countries and 19 states, will pitch during the event, which culminates in the annual recognition of the “Most Promising Companies." The 12 companies that were named to Class 5 of the Rice Alliance Clean Energy Accelerator will present during Demo Day to wrap up their 10-week program.

In addition to pitches, the event will also host keynotes from Arjun Murti, partner of energy macro and policy at Veriten, and Susan Schofer, partner at HAX and chief science officer at SOSV. Panels will focus on corporate innovation and institutional venture capital. Attendees can also participate in one-on-one office hours with founders and investors.

The forum will take place Sept. 18 at Rice University’s Jones Graduate School of Business.

The 2025 presenting companies include:

  • Aeromine Technologies
  • AlumaPower
  • Ammobia
  • Aqua-Cell Energy
  • Aquafortus
  • Aquora Biosystems
  • Arculus Solutions
  • Artemis Production Solutions
  • AtmoSpark Technologies
  • AtoMe
  • Badwater Alchemy
  • C+UP
  • Carbon Blade
  • Circul8 Energy & Environment
  • CO2 Lock
  • Direct C
  • DirectH2
  • Ekona Power
  • Exum Instruments
  • Fathom Storage
  • Flyscan Systems
  • Geokiln Energy Innovation
  • Glint Solar
  • Hive Autonomy
  • Horne Technologies
  • Hydrogenious LOHC Maritime
  • Innowind Energy Solutions
  • Iron IQ
  • Kewazo
  • LiNova Energy
  • Lukera Energy
  • Lydian
  • Mcatalysis
  • Metal Light
  • Mithril Minerals
  • Moment Energy
  • Moonshot Hydrogen
  • Muon Vision
  • PolyQor
  • Polystyvert dba UpSolv
  • Precision Additive
  • RapiCure Solutions
  • Resollant
  • SiriNor
  • Skyven Technologies
  • Sperra
  • SpiroPak
  • Sweetch Energy
  • Teverra
  • Utility Global
  • Xplorobot

Companies participating in office hours include:

  • Active Surfaces
  • Advanced Reactor Technologies
  • Advanced Thermovoltaic Systems
  • Ai Driller
  • Airbridge
  • Airworks Compressors
  • Austere Environmental
  • Brint Tech
  • CarbonX Solutions
  • Cavern Energy Storage
  • Celadyne Technologies
  • CERT Systems
  • CubeNexus
  • Deep Anchor Solutions
  • Ellexco
  • Emerald Battery Labs
  • Equipt.ai
  • FAST Metals
  • FieldMesh
  • FlowCellutions
  • Fluidsdata
  • GrapheneTX
  • GS VORTEX SYSTEMS
  • Installer
  • Kanin Energy
  • MacroCycle Technologies
  • Modular MOPU
  • NANOBORNE
  • NetForwards
  • Oxylus Energy
  • PetroBricks
  • PHNXX
  • RASMAG Energy
  • RedShift Energy
  • RENASYS
  • RenewCO2
  • Resonantia Diagnostics
  • Respire Energy
  • Safety Radar
  • SeaStock
  • Secant Fuel
  • SolGrapH
  • Stratos Perception
  • Terraflow Energy
  • Think Energy Holdings
  • Turnover Labs
  • Utiltyx
  • Zenthos Energy

Find information about the full day of events here, or click here to register.

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Houston hypersonic engine company lands $91M to accelerate production

Clean Speed

Houston-based Venus Aerospace has closed a $91 million Series B round and plans to scale the production of its hypersonic engine.

The round was led by Houston-based Mercury Fund with participation from Lockheed Martin Ventures, MESH, PEAK6, Draper Associates, Starboard Star Venture Capital, Green Sands Equity and other investors, according to a news release.

The investment comes about a year after Venus completed the first U.S. flight test of its high-thrust rotating detonation rocket engine (RDRE). The engine is expected to enable vehicles to travel four to six times the speed of sound from a conventional runway and is about 15 percent more efficient than traditional alternatives, according to the company.

Venus Aerospace says the latest round of funding will allow it to move the RDRE from demonstration to deployment and meet customer requirements for the near-term defense and space industries. The company says that the reusable RDRE is designed with a "common propulsion architecture" that can work for multiple industries and mission types.

“This financing marks an important step in moving Venus from breakthrough demonstration to scaled capability,” Sassie Duggleby, co-founder and CEO, said in the news release. “Our customers need propulsion systems that go farther, can be produced reliably and are built on supply chains they can trust. We are advancing that capability with American engineering and manufacturing talent to strengthen U.S. defense, expand space access and support the future of high-speed flight.”

Venus Aerospace raised a $20 million Series A in 2022, led by Wyoming-based Prime Movers Lab. At the time, the company said it would put the funding toward three main technologies: a next-generation rocket engine, aircraft shape and leading-edge cooling system.

The company also picked up an investment from Lockheed Martin Ventures, the investment arm of aerospace and defense contractor Lockheed Martin, in November 2025—in addition to funding from other investors over the years.

“Since our initial investment, Venus has progressed very quickly in its technology development," Chris Moran, vice president and general manager of Lockheed Martin Ventures, added in the release. "Our reinvestment in Venus recognizes Venus’ accomplishments to date and focus on speed to manufacture, cost management and reduction of supply chain constraints. Venus is working effectively to position its propulsion system for the production scale required by defense programs.”

"Venus is exactly the kind of company Houston capital should be backing," Blair Garrou, co-founder and managing partner at Mercury Fund, added in the release. "It combines multiple frontier technologies, domestic manufacturing and clear commercial and national security relevance. We believe this team is positioned to lead an important new chapter in defense and space, and we are proud to support a company building breakthrough technology here in Texas."

Venus Aerospace and Houston clean tech startup Vaulted Deep were also named to the World Economic Forum's Technology Pioneers community earlier this summer.

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This article first appeared on InnovationMap.com.

14 climatech startups join Greentown Houston in first half of 2026

green team

Climatech incubator Greentown Labs reports that 14 startups have joined its Houston community so far this year.

The companies are among 30 new startups to have joined Greentown Houston and Greentown Boston in 2026. Four of the companies are headquartered in Houston.

The startups are working on a range of "hydrogen-powered heavy-duty transport to AI-driven grid interconnection," according to Greentown.

The local startups that joined Greentown Houston include:

  • Houston-based Focis AI, which transforms industrial laser scans into structured asset intelligence to automatically identify, classify and map components in refineries and plants
  • Houston-based Iron Lattice, which develops next-generation memory technology for AI and high-performance computing that improves energy efficiency, endurance and scalability while remaining compatible with existing semiconductor manufacturing
  • Houston-based Orbital Arc, which is developing a new ion engine designed to improve the efficiency and scalability of spacecraft propulsion from low Earth orbit to deep space
  • Houston-based Sustain Energy LLC, which delivers cleaner, lower-cost fuel to industrial customers in pipeline-absent, underserved markets, cutting their energy costs and emissions with no infrastructure investment on their end

Other startups from around the world joined the Houston incubator in the same time period, including:

  • Ankara-based AIS Field, which develops robotic, AI-assisted non-destructive inspection systems, including submersible tank and boiler crawlers
  • San Francisco-based Armada AI, which builds rapidly deployable modular and edge data centers that run on local, stranded, or renewable power
  • San Francisco-based Armeta, which turns complex engineering drawings and legacy documentation into structured, usable data
  • Pittsburgh-based Atlas Robotics, which develops a Physical AI platform that powers autonomous material-handling robots and AI-guided forklifts
  • Ghana-based Cocoa Potash, which transforms high-emissions agricultural waste from cocoa, coconut, and palm-nut into organic potash, fertilizer and renewable energy
  • Israel-based Criaterra, which produces low-carbon, cement-free building materials
  • Italy-based ETAK, which manufactures modular reactors that convert solid waste into clean syngas
  • Kenya-based FelixFusion, which uses its Felix platform to model every grid connection point, including capacity, upgrade costs, and constraints
  • San Diego-based Gemini Energy, which builds next-generation fuel cells for data-center power
  • Tokyo-based Hibot, which develops robotic systems for inspecting and maintaining infrastructure in hazardous, hard-to-access environments
  • Austin-based Sheetak, which designs and manufactures thermoelectric coolers, generators, and assemblies for solid-state cooling and energy harvesting
  • The Netherlands-based ToPerform, which makes AI-powered, non-intrusive fouling sensors that monitor pipelines around the clock and predict the optimal cleaning time

Another 16 startups joined Greentown's Boston incubator. See the full list of new members here.

More than 100 startups joined Greentown last year, according to an end-of-year reflection shared by Greentown CEO Georgina Campbell Flatter. Read more about them here.

Houston cleantech startup secures $134M to develop ‘superhot’ geothermal plant

deep round

Houston-based Quaise Energy, a producer of utility-scale geothermal power, raised $134 million in a Series B round to advance its “superhot” geothermal power plant.

Climate-focused San Francisco-based investment firm Prelude Ventures led the round, with participation from JERA Co., Japan’s largest power generation company, and Idemitsu Kosan, one of Japan’s largest energy companies. Nearly all existing investors, including cleantech-focused investment firm Safar Partners, participated in the round.

“We have backed Quaise since the beginning because we believed accessing superhot rock would unlock geothermal energy at a scale the world has never seen,” Mark Cupta, managing director at Prelude Ventures, said in a press release.

The startup expects more equity and debt deals to close “imminently.” Quaise has raised $230 million since its founding in 2018.

Quaise says some of the fresh funding will go toward building the world’s first commercial-scale “superhot” geothermal power plant —Project Obsidian in central Oregon. In addition, Quaise is earmarking money for continued development and commercialization of its millimeter-wave drilling system toward depths exceeding 5 kilometers (about 16,400 feet).

Quaise uses a millimeter-wave drilling system developed at the Massachusetts Institute of Technology to remove rock at depths and temperatures that aren’t economically feasible with conventional drilling. With this technology, Quaise can reach rock at temperatures of around 570 degrees to 930 degrees in most places worldwide, enabling construction of geothermal systems that rival fossil fuels and nuclear energy in power density and that rival renewables in cost.

“Our ambition is to power civilization with Earth's most compelling energy source. This round takes us from field-proven technology to first commercial revenues,” Carlos Araque, co-founder, president and CEO of Quaise, added in the release.

Quaise has demonstrated the capability of its millimeter-wave drilling system at its Central Texas test site, drilling more than about 330 feet through granite in 2025—the first time the technology penetrated basement rock at full scale in the field. The company is approaching a depth of about 3,300 feet at the same site.

Construction of Project Obsidian is underway at Oregon’s Deschutes National Forest. The project, which has the potential to generate gigawatt-scale power, is slated to deliver electricity to the Pacific Northwest grid by 2030.