Cleantech Open

What Cleantech Open does

Cleantech Open is a Palo Alto, U.S.-based nonprofit organization founded in 2005 that operates the world's largest cleantech accelerator program. It runs an annual cohort-based accelerator serving 100-150 early-stage cleantech startups (typically pre-Series A, with less than $2M in private funding and less than $10M from family/friends/grants) through a structured curriculum: a 12-week series of workshops, bootcamps, and webinars covering customer discovery, business modeling, financial modeling, investor pitch preparation, and sustainability planning (GHG ERP calculations). Each participating startup is matched with up to four volunteer mentors and must complete Essential Business Deliverables to graduate. Programs are delivered across seven U.S. regional divisions (West, Northeast, Midwest, Southeast, South Central, Rocky Mountain, Pacific Northwest), with regional winners advancing to the annual Global Forum co-located with the VERGE climate conference in San Jose. The organization also operates the Global Ideas international pitch competition and a CTO France affiliate. Since 2005, Cleantech Open has trained over 4,000 entrepreneurs from 2,100+ startups, with alumni collectively raising $3B+ in external equity; 70%+ of U.S. alumni remain operating.

The business model is a hybrid of program participation fees, corporate/foundation sponsorship, and individual donations processed through fiscal sponsor Community Partners (a 501(c)(3)). Startups pay application fees ($30 early bird / $80 regular) and participation fees ($1,875 for student-led teams, $2,600 early bird / $2,950 regular per company for up to two members). Corporate sponsors — including Wells Fargo as National Premier Sponsor, Breakthrough Energy Fellows, NREL, and CalSEED at the national tier, and regional Platinum/Gold/Silver/Bronze sponsors — provide the majority of operating funding alongside in-kind contributions (e.g., AWS credits, Sidley Austin legal services). Up to $150,000 in cash plus $50,000 in in-kind services are awarded annually to regional and national winners. The program is delivered through 2,000+ volunteer mentors, 30+ Metro Ambassadors across U.S. cities, regional staff, and a partnership network spanning 40+ ecosystem organizations (Greentown Labs, LACI, New Energy Nexus, Cyclotron Road, Elemental Excelerator, Berkeley Lab, Plug and Play, Keiretsu Forum). GTM motion is community-led and event-driven: applications open February 1 and close April 6 annually, with recruitment through kickoff webinars, regional meetups, monthly newsletters, alumni advocacy, and partner cross-promotion.

Name

Cleantech Open

Legal name

Cleantech Open

Website

http://www.cleantechopen.org

Company type

Private

Founded year

2006

Operating status

Operating

Headcount range

1,001–5,000 employees

Short description

Cleantech Open is a U.S. nonprofit that runs the world's largest cleantech accelerator, training 100-150 early-stage startups annually across seven U.S. regions plus an international track, supported by 2,000+ volunteer mentors and corporate sponsors.

Ownership category

akta.pro rank

Product category

Startup Accelerator Services

NAICS

Computer Systems Design and Related Services (54151), Business Schools and Computer and Management Training (6114)

SIC

Services-Computer Integrated Systems Design (7373)

akta.pro primary industry

Accelerators & Incubators (Investor-Operated) (FSANAAAM)

akta.pro secondary industry

Youth Business Incubators & Accelerators (EDAMAHAC)

Keywords

• Cleantech accelerator
• Startup business accelerator
• Clean technology incubator
• Mentorship program
• Venture pitch competition

Headquarters

HQ city

Palo Alto

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Marketing or Sales, Operations, Technology or R&D

Revenue model

1. Program Participation Fees: Early-stage cleantech startups pay application fees ($30 early bird, $80 regular) and participation fees ($1,875 for student-led, $2,600 early bird, $2,950 regular) to join the accelerator. Fees cover training, mentoring, and event participation including receptions and meals.
2. Corporate and Foundation Sponsorships: Major corporate sponsors (Wells Fargo, Breakthrough Energy Fellows, CalSEED) and regional sponsors provide funding, in-kind services, and prize money. National Premier Sponsors and regional sponsors at Platinum/Gold/Silver/Bronze tiers support the accelerator program.
3. Individual Donations: Tax-deductible donations accepted through fiscal sponsor Community Partners (501c3). Donations support program operations and startup support.

Pricing tiers

Go-to-market motion2 records

Distribution channels5 records

Marketing channels9 records

Core offering

Cleantech Open operates the world's largest cleantech accelerator program, providing an annual cycle of structured mentoring, business development workshops, customer discovery, investor introductions, and corporate matching to 100-150 early-stage cleantech startups. The program includes regional cohorts, a culminating national Global Forum showcase, an international Global Ideas track for non-U.S. startups, and post-program alumni support such as Cleantech Navigate Northeast.

Product overview

Cleantech Open operates the world's largest cleantech accelerator program consisting of multiple integrated offerings: the US Accelerator as the core program providing 100-150 companies annually with structured mentoring, training, and investor access; the Global Ideas Pitch Competition for international startups; the annual Global Forum as the culminating showcase event; seven Regional Accelerator Programs spanning the US from West to Northeast; and international extensions including CTO France. The programs are interconnected—regional winners advance to national competitions at the Global Forum, and alumni can access post-accelerator support through programs like Cleantech Navigate Northeast.

Differentiator

Problem solved

Functional benefit

Products and services

• US Accelerator Flagship annual accelerator program providing 100-150 early-stage U.S. cleantech startups annually with a 12-week curriculum, up to four volunteer mentors, customer discovery, business model development, investor introductions, regional showcases, and competition for up to $150,000 in cash prizes plus $50,000 in in-kind services.
• Global Ideas Pitch Competition Annual international competition for cleantech startups based outside the USA with under $3M USD equity raised and under $5M USD annual revenue; Top 6 finalists pitch at the Global Forum and gain networking access to U.S. investors and corporates.
• Global Forum Annual culminating event featuring startup showcases, the National Finals pitch competition, CTO Awards Ceremony, Investor & Partner Connect sessions, and co-location with the VERGE climate conference drawing 4,000+ professionals.
• Regional Accelerator Programs
• Cleantech Open France (CTO France) International extension of the Cleantech Open accelerator program serving the French market in partnership with CTO France.
• Cleantech Navigate Northeast Post-accelerator program helping accelerator participants and alumni connect with financiers, strategic partners, and early-adoption customers.

Quantifiable outcome

• More than 70% of reporting U.S. alumni companies are still operating and have collectively raised over $3B in external funding
• +3 more outcomes

Named customers13 records

Segments3 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

15 partnerships are on record, tiered core, flagship and minor.

• IN2 Innovation Incubator (Wells Fargo)coreTechnology or IntegrationThe Wells Fargo Innovation Incubator (IN2) is a technology incubator platform that provides funding and support to select Cleantech Open alumni companies for technology validation and commercialization.
• NREL (National Renewable Energy Lab)coreStrategic or Co-development PartnerNational Sponsor enabling the accelerator program and Global Forum. NREL provides technical expertise and validation resources for cleantech startups in the program.
• GreenBiz GroupcoreStrategic or Co-development PartnerPartner organization co-locating the annual Global Forum with the VERGE climate tech conference, providing access to 4,000+ climate professionals and cross-promotional opportunities.
• ACT | The Alliance for Climate TransitionflagshipStrategic or Co-development PartnerNortheast Regional Affiliate of Cleantech Open, executing the Cleantech Open Northeast accelerator program. ACT provides office space, staff, and visibility while CTO helps promote ACT's interests and creates a pipeline for potential new members.
• Greentown LabscoreStrategic or Co-development PartnerMajor cleantech hardware incubator and maker space in Somerville, MA. Partnership provides co-marketing, event collaboration, and startup pipeline access for the Northeast region.
• LACI (Los Angeles Cleantech Incubator)coreStrategic or Co-development PartnerLeading LA-based cleantech incubator partnership for cross-promotion, event collaboration, and startup referral in the West region.
• New Energy NexuscoreStrategic or Co-development PartnerInternational organization supporting clean energy entrepreneurs. Partnership enables cross-promotion and ecosystem collaboration globally.
• Cyclotron RoadcoreStrategic or Co-development PartnerLawrence Berkeley National Lab's entrepreneurial fellowship program. Partnership enables collaboration on hardtech/climate entrepreneurship support.
• Elemental ExceleratorcoreStrategic or Co-development PartnerClimate technology accelerator focused on hardware and infrastructure. Partnership enables startup referrals and ecosystem collaboration.
• Berkeley LabcoreStrategic or Co-development PartnerLawrence Berkeley National Laboratory partnership for technical validation, research collaboration, and startup support.
• Plug and Play Tech CenterminorChannel Partner/ Reseller/ DistributorGlobal innovation platform connecting startups with corporations. Partnership enables referral of promising cleantech startups and corporate engagement.
• VERGE (GreenBiz)flagshipStrategic or Co-development PartnerVERGE 25 climate tech conference co-located with the 2025 Global Forum in San Jose. Provides venue (San Jose Convention Center Hall 3), 4,000+ professional attendees, and marquee visibility for CTO startups.
• Community PartnerscoreOthersFiscal sponsor, a 501c3 non-profit organization based in Los Angeles that receives and acknowledges all donations on behalf of Cleantech Open. All donations are tax deductible.
• NewlabcoreStrategic or Co-development PartnerBrooklyn-based center of invention providing lab space for startups developing prototypes. Hosted the 2025 Cleantech Open Northeast Regional Finals at their facility.
• CTO FrancecoreStrategic or Co-development PartnerInternational affiliate of Cleantech Open operating in France, extending the global cleantech innovation ecosystem to Europe.

Scale indicators10 records

Recent moves7 records

Expansion highlights5 records

Broad incumbents

• Techstars: Techstars is a global for-profit accelerator running vertical-specific programs including cleantech and sustainability tracks. It is comparable as a large accelerator serving early-stage startups but operates a much broader portfolio beyond cleantech.
• Plug and Play Tech Center: Plug and Play is a global innovation platform with corporate venture and accelerator programs across many verticals including sustainability and mobility. It is a Cleantech Open partner and comparable in connecting startups to corporates, but operates across far broader industries.

Direct peers

• Greentown Labs: Greentown Labs is the largest cleantech hardware incubator in North America, providing lab space, prototyping facilities, and corporate partnerships to early-stage cleantech startups in Somerville, MA. It directly overlaps Cleantech Open's cleantech startup support mission and is listed as a Cleantech Open partner.
• Springboard Enterprises: Springboard is an accelerator network supporting women-led growth companies, including a Climate Tech program focused on female founders. It is comparable in accelerator structure and aligns with Cleantech Open's strong track record of teams with women and BIPOC founders (76% in 2024 cohort).
• New Energy Nexus: New Energy Nexus is an international organization supporting clean energy entrepreneurs through accelerators, funding, and ecosystem programs across the U.S. and globally. It is a Cleantech Open partner and runs comparable cleantech startup programming worldwide.
• Elemental Excelerator: Elemental Excelerator is a climate technology accelerator focused on infrastructure, mobility, and energy startups, deploying equity-free capital and connecting founders with corporate and government partners. It is a Cleantech Open partner and operates in a closely comparable cleantech accelerator niche.
• MassChallenge: MassChallenge is one of the largest global startup accelerators, running industry-specific tracks including a Climate & Energy program with similar mentor-driven, cohort-based structure. It is comparable to Cleantech Open in scale, nonprofit accelerator model, and global reach.
• Cyclotron Road: Cyclotron Road is a deep-tech and cleantech entrepreneurial fellowship at Lawrence Berkeley National Lab that supports scientist-founders building hardtech companies. It is a Cleantech Open partner and overlaps directly in serving early-stage hardtech and cleantech founders.
• LACI (Los Angeles Cleantech Incubator): LACI is a leading LA-based cleantech incubator providing workspace, programming, and corporate introductions to early-stage clean technology startups. It is a Cleantech Open partner and serves the same West region startup ecosystem.

Others

• Keiretsu Forum: Keiretsu Forum is a global angel investor network that is a Cleantech Open partner, providing investor access and mentorship to accelerator startups. It is an ecosystem enabler for Cleantech Open rather than a direct accelerator competitor.

Market position

Strengths5 records

Weaknesses4 records

Competitive moat5 records

Key risks5 records

Key highlights7 records

Customer concentration

• Xx.com/cleantechopen
• LinkedInlinkedin.com/company/cleantech-open
• Facebookfacebook.com/Cleantechopen

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Funding overview

Funding rounds

Investors

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M&A

Investments864 records

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Frequently asked questions about Cleantech Open