2021 CTO Accelerator

National Live Pitch

The application period is now CLOSED!

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.

Why Apply

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 a SAFE note.

How to Apply

1. Step One: Start your startup's profile & registration.

Create a startup profile using the Complete Application Button. Choose the "Startup Registration" option on the left-hand side of the screen.

2. Step Two: Start your application.

Click Complete Application Button from your dashboard after your profile has been submitted.

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.

3. Step Three: Submit your completed application before the final deadline.

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.

4. 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!

5. Step Five: Receive judging feedback and acceptance decision.

After the final deadline of April 18th, you can expect to hear back from us by May 8th 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. 

Dates and Fees

Application Deadline and Fee

The application period is open until 11:59 PM PST on April 18th.   

The application fee per company is $30 THROUGH February 28th. 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.

We will notify applicants by Friday, May 8th.

Important Program Dates

Each company will need to participate at our virtual kick-off event the National Academy, June 2-4. Each company will need to participate in our capstone event at the end of the Accelerator the Global Forum, October 20-22.

The Accelerator is from June 7th until August 29th. There will be other important dates that we will notify you of during the Onboarding webinar for accepted companies in May.

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? Please view the FAQs tab. 

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 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. 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. Travel and accommodation costs are at the expense of the participating company and its members. For the 2021 Program, the National Academies will be virtual-only events and it is possible to participate in the full Accelerator virtually. Participation is still required. Participation will be required throughout the summer but they will become virtual events as necessitated.

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. For the 2021 Program, the National Academies & Global Forum will be virtual-only events. Participation is still required. Participation will be required throughout the summer but they will become virtual events as necessitated.

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.

7) For International Companies

Startups located outside the United States are welcome to participate in the Accelerator, and eligibility and costs are the same as for US companies. You should be considering doing business in the United States in the near future - our accelerator is all about building a network for the American market.

You must have very good English ability as all activities will be done via Zoom and other web conferencing platforms. Finally, you must be able to attend events that are typically scheduled between 8 AM and 3 PM Pacific Time (Los Angeles), so be aware of any time zone difference to your location. In 2021, due to the continuing pandemic, travel to in-person CTO events will not be required, which can save on travel expenses.

Judging Criteria

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?


What qualifies as a student-led company

To qualify as a student-led company, the company must have a full-time student as the lead for the Accelerator, and at least half the company must be students.

What if I plan to raise a round of funding while participating in the Accelerator? Am I still eligible?

Yes - as long as you fall within the funding guidelines at the time of your application, your startup is still eligible.

Should my technology be at a certain stage of development before I apply?

No - we accept startups at all stages of development. We have had winning teams who started the program with only a concept and no prototype, and we had winning teams who were already selling a product to customers!

That being said, the curriculum and program of Cleantech Open is most useful for companies who are still doing Customer Discovery, creating their Business Models, and forming their products.

Do I need an already established company to apply to the Accelerator?

No - you can be a team of at least two individuals or a company (eg corporation or LLC), although in order to pay out any prize money at the end of the competition, you would need to be a company and provide a W9 form.

You may form a brand new team in order to apply, but we recommend applying with an existing team (you will get more out of the Accelerator with a team that is already established and has a clear definition of roles).

Does my company need to be a US legal entity to apply to the Accelerator?

No. However, a US legal entity (corporation, LLC, or similar) must be created prior to receiving any prizes (we can't write checks to individuals). Any such legal entity must have an ownership structure typical of an independent startup.

Do you offer fee waivers or refunds for the application fee.

No. We don't typically offer fee waivers nor do we refund the application fee. Please read through all FAQs and ask Cleantech Open HQ for clarification before paying the application fee.

What if you only have one company member?

One of our basic requirements is that there needs to be a minimum of two people per company. However, sometimes the second company member doesn't have to participate in the program full-time. Most often, only one company member needs to attend most events. If you are really pressed for a second company member, check out sites like or CoFoundersLab to find other entrepreneurs, or try to enlist an advisor/mentor from outside Cleantech Open to join your team

What is the time commitment like?

As with most activities, you will get out of Cleantech Open what you put into it. We've tried to design the program so that it integrates into your schedule rather than takes time out of it.

Alumni have said they spend 2-8 hours per week on Cleantech Open-related activities at any given point during the accelerator. Participation is required in the National Academy (June 2-4)) and Global Forum (October 20-22) events are typically 2-3 days in conjunction with a weekend day. The National Academy and Global Forum will be virtual for 2021.

Cleantech Open is for very early-stage companies. We're really focused on finding customers right now, and we're concerned Cleantech Open will be a distraction.

We hear frequent concerns on both sides of this issue (see below). Yes, it's true, at its heart this program supports early stage startups, but we actually work with a wide range of companies in different developmental stages. We frequently work with teams that have slugged it out for several years and are in need of a few key connections, some new inspiration, that one big seed opportunity, and some great visibility to get their idea to market.

A big part of our program is focused on finding and speaking with customers:  finding them, learning about their needs and determining how your company and technology can fulfill those needs.  Cleantech Open is about finding the best of the next crop of companies that have put in blood, sweat, and tears and are primed to take advantage of the massive opportunity that our program provides.

We are too early stage for the Cleantech Open Accelerator.

We love early-stage ideas - many of us take a great personal interest in finding out about these and doing what we can to make them real ventures. Often people are too modest or not sure they're ready to get their idea out there and act on what they have to offer. But if you are just starting up, there is no better way than the Cleantech Open Accelerator to focus on business strategy, with guidance from some of the best professionals in the field! Some of our most successful companies came through the Cleantech Open at a very early stage in their process and are now off and running.

I don't have time to focus on anything besides growing my business.

Great - then Cleantech Open is perfect for you because it is all about growing your business! Trust us, no one can understand being busy better than us. In many ways, Cleantech Open is like a startup ourselves, with only TWO full-time staff people year-round! Our volunteers give up a huge chunk of their free time because they care about companies like yours.

Our alumni will tell you that the exercises that they went through in the Cleantech Open were what they would have had to do anyway, just on a structured time frame with guidance from mentors. This is not an academic exercise or passive program of lessons.

Cleantech Open is a structured, in-depth, and COMMUNITY-DRIVEN process where we expect you to come out a stronger and more primed company on the other end. The core of the program can take as little as a few hours each week, but you'll find that the accelerator's ongoing intangible benefits reach far beyond that. If you don't put your company out there, you'll miss out on the serendipitous, unexpected connections that can occur as a program participant.

I applied and didn't get in previously, why would anything be different now?

Some of our most successful alumni are repeat applicants! Often, companies apply before they're completely ready, and sometimes companies just don't come across well in their first application attempt. That's why we encourage people to re-apply even if they've been passed over before - please let us know how things have changed and what milestones you've hit.

I'm not sure I want to spend the money (participation fee) if I'm accepted.

Cleantech Open is a bargain. We aren't just saying that. We've heard of one-day pitch events charging more than what we charge for a 5-6 month program. If we were to charge you full price for everything we were offering, the cost would be >$10,000 per company. If you come to every event, you will get paid back in food alone.

Our large community of professionals are all contributing their time pro-bono to create value for your startup. By paying a participation fee, you're covering the bare minimum of hard costs that this non-profit organization incurs to run smoothly. The value that's added, the jobs that are created, the millions in funding that are raised by our startups all come because of the massive investment in time and expertise of our community.

What is the acceptance rate?

About 30-50% of applicants are accepted as participants. This is not a hard number as it is important to understand that it depends on the quality of applications we receive each year.

How long does it take to complete an application?

It takes only a few moments to create your user profile - the first step. If you have done grants or other accelerator applications in the past, the Cleantech Open application should be a breeze. Most of your time will be spent editing down to our character limits.

If you are starting from scratch, it will take about 2-5 hours total to complete.

How long does the Accelerator run?

Six to seven months, with the three months in the middle being most intense.

Applicants will hear back from Cleantech Open by May 8th whether or not they have been selected to participate in the accelerator. This is the official starting point of the accelerator.

Regional Final Judging and the Innovation Expo and Awards Gala for the Accelerator happen in late September to early October. Nationally, the Accelerator ends at the Global Forum with National Final Judging, Innovation Expo, Investor & Partner Connect, and an Awards Gala in late October.

What is a SAFE note?

As in past years, Cleantech Open awards the prize to the US National Winner as an investment in the company, and on very favorable terms to the entrepreneur. This was described in the application when you signed up for the program.

CTO has adopted the SAFE Note (Simple Agreement for Future Equity), which is a standard document created by the Y Combinator accelerator, revised in 2018, and widely used throughout the startup ecosystem. You can read more about it here.

Our intention is that the SAFE is the easiest, simplest, and most entrepreneur-friendly way to provide this prize, and it’s compatible with many other forms of fundraising your company may do.

CTO uses the "Discount, No Cap" version, unmodified from the Y Combinator site. For our prize, CTO uses a “0% discount”, meaning there is no discounted pricing owed to CTO at your next round of financing. In addition, unlike typical convertible notes, there is no interest rate, no capped valuation, no expiration, and no expectation of many other rights, for example, board seats. All these terms are more favorable to you, the entrepreneur than typical investors would accept.

CTO encourages the US National Winner to review this SAFE note with their legal counsel and Board of Directors.