Cleantech Open is the world’s largest cleantech accelerator, providing entrepreneurs and corporate innovators the resources they need to launch and grow successful cleantech businesses. Our one-of-a-kind innovation ecosystem built over the last 19 years of programming spans key cleantech innovation hubs in the U.S., linking labs and universities, service providers, investors, corporations, governments, and other cleantech incubators and accelerators. Through our annual accelerator, we provide between 100-150 companies in the U.S. with a rich program of customer discovery, extensive mentoring, training, investor meetings, startup-corporate matching, and showcasing at both the regional and national levels. Since 2005, more than 70% of our reporting U.S. alumni companies are still operating and have collectively raised over $3B in external funding. Join this exciting community and be a part of our global network of innovation.

The Verizon Community Disaster Resilience Innovation Accelerator powered by MassChallenge is designed to identify and support startups developing next-gen solutions that strengthen community resilience before, during, and after natural disasters. Building on the capabilities of Verizon Frontline and Verizon Innovation Labs, this program invites innovators to create technologies that provide preemptive warnings, hazard mitigation, and robust connectivity in the face of natural disaster events, leveraging Verizon’s 5G expertise to protect lives and strengthen community resilience.

Want to help Congress address challenges to the U.S. power grid? The IEEE-USA Congressional Electric Grid Fellowship places skilled engineers, scientists, and other technical experts in Capitol Hill offices to provide Congress with world-class technical expertise. Eligible candidates should have significant work experience (ideally 7+ years), or the education equivalent, in the electric power industry or related fields as well as expertise in providing scientific, technical, and/or analytical support that could be useful in advancing legislative objectives.

Greentown Labs requests applications from innovative startups with advanced CO2 mineralization and carbonation technologies for materials, including concrete aggregates. Greentown Go Build 2026 with Amazon and the Global CO2 Initiative at the University of Michigan aims to accelerate the development and implementation of sustainable materials to decarbonize building practices for Amazon’s operations and the broader construction industry.

Selected startups will work alongside leading energy utilities to deliver innovative solutions that advance the energy transition. Participants will gather globally, engaging in both in-person and virtual modules, designed to fast-track their progress. The program provides an accelerated path for startups to develop and scale their businesses, pilot solutions and access potential investment opportunities.

Aspiring entrepreneurs aim to tackle the world’s greatest energy challenges. Selected innovators’ core technologies align with NREL’s research mission of leading research, innovation, and strategic partnerships to deliver integrated solutions for an affordable and secure energy future.

West Gate embeds innovators at NREL and pairs them with scientists who specialize in the innovators’ technology areas. Throughout the program’s 2-year runway, innovators work with scientists in NREL’s world-class laboratories to de-risk their technologies, ready them for market, and grow their startup companies.

The Carbon to Value (C2V) Initiative drives the creation of a thriving innovation ecosystem for the commercialization of carbontech solutions that capture, convert, and sequester CO₂ into valuable end products or services—with the support of corporate partners, government leaders, and experts who help foster a robust network for our startups. In its first four years, C2V has supported 35 groundbreaking startups that have raised over $580M in follow-on funding, leading to numerous successful partnerships and 600+ new business relationships, technology advancement, and industry growth.

gener8tor is a nationally ranked accelerator that invests in high-growth startups. gener8tor invests in only five to six companies per program. This means a concierge experience. It focuses all of its time, energy and network on you. gener8tor supports the growth of its startups through our network of experienced mentors, technologists, corporate partners, angel investors and venture capitalists. This accelerator program opens up applications for programs in multiple U.S. cities throughout the year.

T.H.R.I.V.E. Emerging Leaders Reimagined provides entrepreneurship education and training for executives of small, poised-for-growth companies. This intensive executive-level training series offers opportunities for small business owners to work with professional coaches and mentors, gain skills needed to grow, and develop connections with peers, local leaders, and the financial community.

Mark1 is a Developer-as-a-Service for capital intensive, first of a kind industrial climate technologies. We work with technology companies to maximize the opportunity for deploying their first commercial-scale projects. Mark1 helps climate tech innovators develop a faster and less expensive path to bankability. With an experienced in-house team, we co-pilot the process alongside project-specific needs of each participating company, to achieve the project’s development milestones. We support technical and commercial project development and capital strategies.

We provide capital, expertise, and connections to nurture startups specializing in advanced energy systems, industry efficiency technologies, and sustainable solutions. Our particular emphasis is on closed-loop lithium systems, next-gen battery development and supply chain innovations, leveraging Nevada’s unique position in the global energy market. The accelerator aims to develop these innovative startups into thriving enterprises that deliver both economic growth and positive environmental impact.