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Accelerator Atlas
ActiveVerifiedChecked against the program's own website or official documents.

Cleantech Open

Climate & Energy · Run by Cleantech Open (nonprofit) · CA

Verified Jul 22, 2026Official websiteHow to apply

Every field is checked against a primary source where we can. How we verify.

The facts

All fields verified Jul 22, 2026
Terms model
Fee-basedYou pay a fee to take part in the program.
Investment
Not publishedFee now primary-verified on the 2026 accelerator page: participation fee $2,600 early bird / $2,950 regular for up to two members, $1,875 for student-led companies; application fee $30 early bird / $80 regular. No equity taken. Up to $150,000 in total cash prizes and/or investment plus up to $50,000 in-kind; national grand prize delivered as a SAFE (0% discount, no interest, no valuation cap or board seat). 2026 applications ran Feb 1 - Apr 6, 2026 (closed); program May 31 - Aug 25, 2026, National Finals Oct 20-22, 2026 in Boston.
Equity taken
Not publishedFee now primary-verified on the 2026 accelerator page: participation fee $2,600 early bird / $2,950 regular for up to two members, $1,875 for student-led companies; application fee $30 early bird / $80 regular. No equity taken. Up to $150,000 in total cash prizes and/or investment plus up to $50,000 in-kind; national grand prize delivered as a SAFE (0% discount, no interest, no valuation cap or board seat). 2026 applications ran Feb 1 - Apr 6, 2026 (closed); program May 31 - Aug 25, 2026, National Finals Oct 20-22, 2026 in Boston.
Program length
Not published
Format
Hybrid
Location
CA
Cohorts per year
1
Cohort size
large multi-region cohort (2,100+ startups since 2005)
Stage focus
very early / idea to seed
Sub-vertical
cleantech (all sectors), national multi-region accelerator
Demographic focus
Not published
Backers
regional sponsors, utility and corporate partners
Notable alumni
Not published

Terms notes: Fee now primary-verified on the 2026 accelerator page: participation fee $2,600 early bird / $2,950 regular for up to two members, $1,875 for student-led companies; application fee $30 early bird / $80 regular. No equity taken. Up to $150,000 in total cash prizes and/or investment plus up to $50,000 in-kind; national grand prize delivered as a SAFE (0% discount, no interest, no valuation cap or board seat). 2026 applications ran Feb 1 - Apr 6, 2026 (closed); program May 31 - Aug 25, 2026, National Finals Oct 20-22, 2026 in Boston.

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Terms in plain English

Cleantech Open is a pay-to-participate nonprofit accelerator, not an investor, and it takes no equity. For the 2026 program the participation fee was $2,600 at the early bird rate or $2,950 regular for up to two team members, with a $1,875 rate for student-led companies, plus an application fee of $30 to $80. Participants compete for up to $150,000 in total cash prizes and/or investment plus up to $50,000 of in-kind services; the national grand prize is structured as a SAFE with a 0% discount and no interest. Prize money is competitive, so most participants pay the fee and receive training and mentorship rather than a check.

Who this is actually for

Idea-stage to seed cleantech founders anywhere in the US who want structured training, mentors, and a national showcase rather than an investment. It runs seven US regional programs, so it is one of the few options outside the coastal climate hubs. Budget for the participation fee and travel to mandatory events, including the National Academy in New York and finals in Boston.

Application windows

  • 2026 Accelerator: Opens Feb 1, 2026, closes Apr 6, 2026.

    Verified date not recordedSource
  • 2027 Accelerator (window not yet posted; 2026 window ran Feb 1 to Apr 6): Timing expected, exact dates not yet confirmed.

    Verified date not recorded

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Plain-English mechanics, with worked hypothetical numbers.

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Sources

Everything above was checked against these, verified Jul 22, 2026.