Cleantech Open is the world's oldest and largest cleantech startup accelerator program, with a mission to find, fund, and foster entrepreneurs developing solutions for urgent energy, environmental, and economic challenges. Through its annual business competition and accelerator, CTO connects startups with essential resources, mentorship, and a national platform for visibility. Since its inception in 2005, Cleantech Open has trained over 4,000 entrepreneurs from more than 2,100 early-stage clean technology startups, helping them collectively raise over $3 billion in funding. The program is powered by a global network of over 1,000 volunteers and sponsors, fostering collaboration between public and private sectors to drive a thriving global cleantech economy.