Cleantech Open
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.
- Company typePrivate
- Founded2005
- HeadquartersPalo Alto, United States
- Headcount1,001–5,000
- GTM typeB2B
- OfferingServices
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.
Cleantech Open firmographics
Firmographics- Name
- Cleantech Open
- Legal name
- Cleantech Open
- Website
- https://cleantechopen.org
- Company type
- Private
- Founded year
- 2005
- 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
Cleantech Open industry classification
Industry- 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
Where Cleantech Open is headquartered
LocationHeadquarters
- HQ city
- Palo Alto
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
Cleantech Open business model
Business model- GTM type
- B2B
- Offering type
- Services
- Cost components
- Personnel, Marketing or Sales, Operations, Technology or R&D
Revenue model
- 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.
- 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.
- Individual Donations: Tax-deductible donations accepted through fiscal sponsor Community Partners (501c3). Donations support program operations and startup support.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Subscription | One-time | Student-led startup participation |
| Subscription | One-time | Early bird participation (submitted by Feb 28) |
| Subscription | One-time | Regular participation (submitted Mar 1 - Apr 6) |
| Subscription | One-time | Application fee (early bird) |
| Subscription | One-time | Application fee (regular) |
| Subscription | One-time | Prize money and in-kind services |
Go-to-market motion2 records
Distribution channels5 records
Marketing channels9 records
Cleantech Open product offering
Product offeringCore 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
Companies that use Cleantech Open
Customer profileNamed customers13 records
Segments3 records
Ideal customer profiles3 records
Cleantech Open technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature4 records
Cleantech Open partnerships and signals
Strategic signalPartnerships
15 partnerships are on record, tiered core, flagship and minor.
- IN2 Innovation Incubator (Wells Fargo)coreThe 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)coreNational Sponsor enabling the accelerator program and Global Forum. NREL provides technical expertise and validation resources for cleantech startups in the program.
- GreenBiz GroupcorePartner 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 TransitionflagshipNortheast 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 LabscoreMajor 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)coreLeading LA-based cleantech incubator partnership for cross-promotion, event collaboration, and startup referral in the West region.
- New Energy NexuscoreInternational organization supporting clean energy entrepreneurs. Partnership enables cross-promotion and ecosystem collaboration globally.
- Cyclotron RoadcoreLawrence Berkeley National Lab's entrepreneurial fellowship program. Partnership enables collaboration on hardtech/climate entrepreneurship support.
- Elemental ExceleratorcoreClimate technology accelerator focused on hardware and infrastructure. Partnership enables startup referrals and ecosystem collaboration.
- Berkeley LabcoreLawrence Berkeley National Laboratory partnership for technical validation, research collaboration, and startup support.
- Plug and Play Tech CenterminorGlobal innovation platform connecting startups with corporations. Partnership enables referral of promising cleantech startups and corporate engagement.
- VERGE (GreenBiz)flagshipVERGE 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 PartnerscoreFiscal 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.
- NewlabcoreBrooklyn-based center of invention providing lab space for startups developing prototypes. Hosted the 2025 Cleantech Open Northeast Regional Finals at their facility.
- CTO FrancecoreInternational affiliate of Cleantech Open operating in France, extending the global cleantech innovation ecosystem to Europe.
Scale indicators10 records
Recent moves7 records
Expansion highlights5 records
Cleantech Open competitors and assessment
Company assessmentBroad 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
Cleantech Open social profiles
Digital presenceCleantech Open financial estimates
Financial estimateRevenue estimate
Valuation estimate
Cleantech Open leadership team
Management profileNumber of profiles
Profiles13 records
Cleantech Open funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Cleantech Open M&A and investment
M&A and investmentM&A
Investments864 records
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Cleantech Open
What does Cleantech Open do?
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.
Is Cleantech Open a public or private company?
Cleantech Open is a private company. It is classified as nonprofit foundation owned and is currently operating.
When was Cleantech Open founded?
Cleantech Open was founded in 2005. It employs 1,001 to 5,000 people.
Where is Cleantech Open based?
Cleantech Open is headquartered in Palo Alto, United States, in the North America region.
How does Cleantech Open make money?
Three revenue lines are on record. Program Participation Fees are the primary driver. The others are corporate and Foundation Sponsorships and individual Donations.
Who are Cleantech Open's main competitors?
Broad incumbents on record are Techstars and Plug and Play Tech Center. Direct peers are Greentown Labs, Springboard Enterprises, New Energy Nexus, Elemental Excelerator, MassChallenge, Cyclotron Road and LACI (Los Angeles Cleantech Incubator). Keiretsu Forum is listed as an others.
Does Cleantech Open have an API?
No public API is recorded for Cleantech Open.
What industry is Cleantech Open in?
Cleantech Open's product category is Startup Accelerator Services. Its primary akta.pro industry code is FSANAAAM, Accelerators & Incubators (Investor-Operated), with a secondary code of EDAMAHAC, Youth Business Incubators & Accelerators. Its NAICS code is 54151 and its SIC code is 7373.