Join us as we launch our 2025 Cleantech Open program in Portland, OR!

Cleantech Open (CTO) is the world’s oldest and largest Clean Technology Startup Accelerator. Nearly 2,100 early stage cleantech startups successfully graduated our program since 2005. This year, we celebrate 20 years of early-stage cleantech startup support!

Calling Startups!

We are looking for ambitious, innovative entrepreneurs working to solve some of the world’s greatest environmental and economic challenges across 8 broad industry domains: energy generation, energy distribution, energy efficiency, green building, transportation, chemicals & advanced materials, agriculture/water/waste, information & communication technologies.

Our curriculum has evolved over 20 years into a well-honed 12-week program starting in June and running through August, with a final competition in September and Culminating Event in October. By the time you’re through CTO, you’ll have everything you need to pitch to early-stage investors and Climate VCs.

Each startup works through the program with at least one assigned mentor, who guides the startup through the curriculum, offering perspective and feedback. Our mentors are seasoned professionals with startup, corporate, and industry expertise.

Through Cleantech Open, startups gain access to the burgeoning cleantech startup support ecosystem here in Oregon, across the US, and across the globe. Our partners include government programs, corporate innovation offices, investors, professional organizations (e.g. legal, finance, accounting), and NGOs.

We work with startups that have raised <$2M in equity, all the way down to trying to flush out an idea on the back of a napkin. If you’re serious about your business, then we are here to help!