If you have any questions, please check out our application FAQs here.

We are the cleantech experts.

We find, fund, and foster the most promising cleantech startups on the planet.   

Let Us Know You Are Interested in the 2020 Cohort! 


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 10 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. 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 $1.2B in external funding. Join this exciting community and be a part of our global network of innovation. The expression of interest form is NOW OPEN, let us know you are interested in the 2020 cohort here.  


We'd love to get to know you, fill out the expression of interest form to be contacted by a regional representative.  

Accepted applicants to the program work with mentors, access a valuable network of professionals and attend business clinics and webinars that provide them with the skills they need to take their business forward. In the fall, teams present their ideas for regional-level judging and are awarded prizes on the regional level. Finalist teams from regions across the country move on to be showcased in our annual Global Forum. The Global Forum showcase also features a competition among the regional winners where national prizes are awarded. If you are interested in applying to the Accelerator Program, please let us know here.

Volunteers and Mentors

As a non-profit organization with a small full-time staff, Cleantech Open is run largely by volunteers. Our volunteers are united in their passion for clean technology and helping to make a difference in the world. If you are interested in volunteering or mentoring a team, please get started here.



Cleantech Open provides tangible benefits:

  • World-class mentoring: receive intensive, tailored mentoring from experienced business experts and gain access to one of the world's only cleantech-specific expert networks.
  • Hands-on training: 12-week series of intensive workshops, boot camps, and webinars to launch your startup to the next level.
  • Prizes: In 2020, U.S. Cleantech Open plans to award a mix of cash and in-kind services to the winners of its showcasing events. This includes:
    • Up to $75,000 in cash investment* to winners of our regional and national showcasing competitions in the U.S.
    • Up to $50,000 of in-kind services - each cash/investment award will be matched with up to an equal amount in services.
    • The opportunity to win more prizes as they are announced.
  • Networking: connect to a powerful national network of influencers and entrepreneurs.
  • Visibility: showcase your startup to investors, strategic partners, and customers through specialized connection events as well as through social media and press releases.
  • Alumni: on-going engagement for teams who’ve completed Cleantech Open, including introductions to investors and corporate partners, participation in Challenges, networking events.

As with most endeavors, what you get out of Cleantech Open is based on the effort and intensity of what you put in.  Don’t expect to simply sign up and expect to win a prize!

*All awards are subject to change at Cleantech Open’s sole discretion and may vary from region to region. The cash component of each award may be provided as a grant or as seed capital (investment). The grand prize is provided as seed capital (investment) in the form of a convertible note.

We'd love to get to know you, fill out the expression of interest form to be contacted by a regional representative.  

Step One: Let us know you are interested!

We'd love to get to know you, fill out the expression of interest form to be contacted by a regional representative.  Or you can sign up NOW!

Step Two: Speak to a Cleantech Open representative. 

After filling out the expression of interest form, we'll be in touch! 

Step Three: Start your Application.

After creating your startup profile, click on the “Apply" button, or visit your Startup Dashboard and click “Submit". You will be prompted to pay the application fee after you start filling out the application itself but before you can successfully submit it for judging. Please see the Dates and Fees section below for more details. Note that if you would like to preview the application questions and begin working on the application BEFORE submitting your payment, we have provided a downloadable version of the application in the Application Toolkit section below.

Step Four: Submit your completed application before the final deadline.

You can continue to work on your application UNTIL you submit it.  Once it is submitted it moves directly into the judging queue and cannot be modified.  We recommend asking our team any application questions as early as possible, attending our Q&A sessions, and getting a mentor or advisor to review the application as early as possible to avoid a last-minute submission.  The earlier you submit your application the better!

Step Five: Receive judging feedback and acceptance decision.

After the final deadline of April 19th, you can expect to hear back from us by May 6th about whether or not you were accepted into the Accelerator. Regardless of your acceptance decision, our panel of expert judges will review your application and provide you with valuable judging feedback. 

Application Deadline and Fee

The application period is open until 11:59 PM PST on April 19th.  If you are interested in our next cohort or want to speak with someone about how your product/technology/service aligns with Cleantech Open, please let us know here

The application fee per company is $29 THROUGH February 29th. On March 1st, the application fee becomes $75.

*To qualify as a student, the team must have a full-time student as the Company Leader and at least half the company must be students.

Participation Fee

If you are accepted into the program, the fee for participation in the Cleantech Open is $1,350 for up to two members participating per company (or $975 for student-led companies). This covers several months' worth of training, mentoring, and event participation, including receptions and meals. Travel costs and other expenses will not be reimbursed so plan for these additional costs, as attendance at the National Academy (in California or Boston/New York) and Global Forum are required. 

1) Technology

Your technology must fit into one of these categories.

  • Energy Generation
  • Energy Distribution & Storage
  • Energy Efficiency
  • Chemicals & Advanced Materials
  • Information & Communications Technologies (ICT)
  • Green Building
  • Transportation
  • Agriculture, Water & Waste

Confused about how your technology fits? Read our FAQ

2) Funding 

Cleantech Open supports early-stage startups.  Most startups in our program have less than $1.5MM in funding from private investors or less than $10MM in funding from family, friends, and grants.  There are exceptions, however, and we encourage you to apply even if your funding levels are higher.  We'll evaluate your fit with the program holistically, considering your company's ability to benefit from the program.

3) Company

You must have at least two members.

4) Location

Much of the value Cleantech Open creates for participating startups is centered around relationships and network connections.  For this reason, it is important for your team to physically participate in the Cleantech Open events over the program year, including the National Academy (East or West), Business Clinics, Workshops, Networking events, Regional Awards & Innovation Showcase, and our Global Forum (now part of Cleantech Week).  Please confirm that you'll be able to participate in our program in this way AS THE NATIONAL ACADEMY AND GLOBAL FORUM ARE REQUIRED EVENTS. 

5) Participation

At least one team member must actively engage with the Accelerator by participating in meetings or events that are part of the program, and by submitting final deliverables before Final Judging. There are only two mandatory events at the National level: 1) the National Academy (you choose East or West) and 2) the Global Forum.  There are several mandatory events at the Regional level: 1) Business Clinics and 2) Regional Showcase.

6) Conflict of Interest

You MAY NOT apply if you are an Accelerator volunteer, judge, expert, advisor, mentor, chair, regional director, or if you are in any other way involved with the organization or operation of the accelerator. Immediate family members of the aforementioned people are also ineligible.

You MAY apply if you are affiliated with the accelerator's sponsors and/or partners, as long as you or a family member are not directly involved in the operation of the Cleantech Open, as above.

If you are accepted as an entrepreneur or company participating in the Cleantech Open Accelerator, individuals involved in the running of the Cleantech Open may advise or mentor you, within the rules of the Accelerator, but such individuals may not take a direct interest in your company (such as an equity stake or a paid position) and may not participate as company members until after the Global Forum in the year of your participation.

For our organization, clean tech has a broad definition and encompasses a lot of different technology categories. In addition, startups who get into our program are often at very diverse stages of development. In other words, there is certainly no 'perfect' candidate for the Accelerator.

When judges look at your application, they will be evaluating your entry on the following criteria:

  • Team Is the company's team promising and credible? Have gaps been identified clearly? Do they seem able to attract additional quality team members?
  • Technology Is the technology potentially disruptive? Does it demonstrate the potential for a sustainable competitive advantage?
  • Market Is the potential market size large enough for sustained business growth, and aligned with the expectations of possible funding sources?

Check out our application FAQ first to see if your question is answered there.

Check out our application FAQ first to see if your question is answered there.