Yokohama×Greennex Global: 7 Frontier Climate Innovations Showcased at New York Climate Week’s U.S.–Japan Startup Pitch

As climate challenges intensify worldwide, cross-border collaboration has become one of the most powerful engines driving innovation. The Yokohama Clean Tech Gateway: U.S.–Japan Morning Pitches—co-organized by the City of Yokohama and Greennex Global—was held during New York Climate Week 2025 as part of the Smart City Collaboration Forum, spotlighting some of the most ambitious U.S. climate tech startups to an exclusive group of Japan’s leading investors and corporate stakeholders.

The event opened with remarks from Masahiro Nishikawa, Director of the Office of the City of Yokohama Representative to the Americas, who set the tone for a morning centered on building genuine partnerships between two dynamic innovation ecosystems. A highlight of the opening was Sun Metalon, a Yokohama-born startup pioneering zero-emission metal recycling—transforming contaminated industrial waste into high-value materials. Their story exemplified how Yokohama nurtures homegrown innovations while fostering global collaboration.

U.S. Startups Showcasing the Future of Climate Infrastructure

Seven cutting-edge ventures from across the U.S. were selected to pitch breakthrough solutions across key verticals—including grid orchestration, EV infrastructure, carbon removal, thermal storage, and next-gen battery materials.

Collectively backed by top-tier climate and infrastructure investors such as Breakthrough Energy, Toyota Ventures, AWS, Newlab, Greentown Labs and Activate, these startups are already piloting across U.S. states, partnering with Fortune 500 companies, and proving their technologies in real-world deployments. Their founding teams trace deep technical roots to MIT, Columbia, and Northwestern University, with use cases spanning municipal EV retrofits, industrial grid integration, and carbon capture at scale.

Among the ventures spotlighted were:

• Voltpost – Lamppost-based EV charging that converts existing street infrastructure into curbside climate solutions.

• Arbon – Columbia spinout developing modular, humidity-swing direct air capture systems with novel sorbent materials.

• Elementium Materials – MIT spinout advancing next-gen battery electrolytes for faster, longer-lasting, and safer energy storage.

• Harvest Thermal – Smart thermal battery integrating heat pumps and intelligent controls to cut home emissions by 90%.

• Cella – Permanent CO₂ mineralization using modular reactors for scalable, durable carbon removal.

• Teknobuilt – AI-powered project delivery software accelerating clean infrastructure across Asia and the Middle East.

• Camus Energy – A grid orchestration platform powering virtual power plants and real-time flexibility, directly relevant to Japan’s distributed energy transition.

From Local Innovation to Global Pathways

The session convened more than 70 curated participants, underscoring strong institutional commitment to U.S.–Japan climate tech collaboration. Distinguished guests included Dilip Chauhan, Deputy Commissioner at the NYC Mayor’s Office for International Affairs; Josefina Echeverria of NYCEDC; and Kazuma Yamamoto, Deputy Consul-General of Japan in New York.

Over 60 senior leaders from Japan’s most strategic institutions also joined, representing the Development Bank of Japan, Mitsubishi Corporation, ENEOS Americas, Daikin Industries, INPEX New York, the Japanese Chamber of Commerce and Industry of New York (JCCINY), ITOCHU International, SCSK Corporation, Asahi Kasei Ventures, Marunouchi Innovation Partners, JERA Ventures, and Kanematsu Ventures—among many others. Their presence reflected Japan’s broad commitment—from banking and heavy industry to energy conglomerates and venture capital—to explore partnerships with U.S. climate innovators.

Closing the session, Stella Song, Founder of Greennex Global and curator of the featured startup pitches, emphasized that the internationalization of climate tech demands more than capital—it requires long-term, cross-border alignment. “It’s exactly because of these joint efforts that, even with headwinds ahead, the gateway remains wide open—capturing the momentum we are building together.” The event highlighted that today’s collaborations are the foundation for even greater international partnerships to come.

Stay Connected

This roadshow is part of the Greennex Global Country Roadshow Series.

Greennex Global is a financial advisory platform focused on cross-border investment into climate ventures, working with governments and strategic capital partners in more than 10 countries to help international investors connect with U.S.-based climate tech opportunities.

For tailored startup introductions or to learn about upcoming roadshows, contact info@greennexglobal.com.

As Japan’s second-largest city and one of Asia’s most globally connected ports, Yokohama has positioned itself as a gateway for smart city innovation and climate collaboration. Through initiatives like the Yokohama Smart City Project and its dedicated U.S. office, the city builds bridges between American startups and Japanese markets—offering soft-landing services, ecosystem navigation, and investor introductions. This partnership with Greennex Global reinforces Yokohama’s role as a true gateway city, ensuring U.S. climate ventures find both capital and collaborative pathways into Japan. Learn more: businessyokohama.com