The Cleantech Open is the world's largest clean technology business competition and incubator program, launched in 2006. It accelerates cleantech startups in sectors like energy, transportation, and green building by providing training, mentoring, and opportunities to win startup funding prizes. Over 190 teams have competed, and 80% of alumni companies remain viable. Alumni have raised over $150 million. The program is expanding to new regions in the US and internationally to foster more cleantech startups and jobs.