Cleantech innovation is not short on ideas. What early stage founders often lack is structured support, real customer validation, and access to the right people at the right time. That is exactly the gap the Cleantech Open Accelerator was built to fill.

As the world’s largest cleantech accelerator, Cleantech Open has spent nearly two decades helping entrepreneurs move from concept to scalable business. If you are a small business owner, innovator, or early stage founder working in cleantech, climate, energy, or sustainability, this program is designed for you.

What Makes Cleantech Open Different

Cleantech Open is not a short workshop or a pitch competition that ends after demo day. It is a deeply integrated accelerator built around execution.

Over 19 years of programming, Cleantech Open has developed a national innovation ecosystem that connects startups to universities, national labs, service providers, investors, corporations, governments, and other accelerators. Each year, between 100 and 150 companies across the U.S. participate in the annual accelerator, gaining access to a structured pathway for growth.

The results speak for themselves. Since 2005, more than 70 percent of reporting U.S. alumni companies are still operating and have collectively raised over $3 billion in external funding.

What You Gain as a Founder

Cleantech Open provides practical, founder focused support designed to help early stage teams move forward, including:

  • World class cleantech specific mentorship from experienced business and technical experts

  • Hands on training through a structured 12 week program covering customer discovery, business models, go to market strategy, and fundraising readiness

  • Meaningful connections to a national network of entrepreneurs, investors, and corporate partners

  • Regional and national showcasing opportunities that increase visibility and credibility

  • The opportunity to compete for cash and in kind awards, plus ongoing alumni support through investor access, challenges, and networking

The value founders gain from Cleantech Open is directly tied to their level of commitment and engagement in the program.

Why Apply Early

The application deadline is Monday, April 6. Applying early gives your team more time to engage with program resources and prepare for the accelerator experience. It also signals readiness and commitment, both of which matter in competitive programs. Apply by February 28 to qualify for a $30 application fee and receive $350 off the program cost.

Cleantech Open is best suited for founders who are ready to test assumptions, engage deeply with mentors, and put in the work required to build a viable cleantech business. Learn more and apply here.

Wrap Up

Building a cleantech startup is hard, but doing it alone is harder. Cleantech Open offers a proven framework, a national support network, and the accountability early stage founders need to move faster and smarter. If you are serious about turning your innovation into a scalable business, now is the time to apply and join a global community of cleantech leaders.

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