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Top Climate tech companies in San Francisco

Companies decarbonising power, transport, agriculture, and industry. Filtered to companies headquartered in San Francisco.

Built from a search like: “Top Climate tech companies in San Francisco”

Ranked by current headcount across Climate tech companies headquartered in San Francisco. Refreshed daily.

  1. 1
    Recology· San Francisco, California, United States
    • 1.3k employees
    • Founded 1920
  2. 2
    d.light· San Francisco, California, United States
    • Debt
    • 1.1k employees
    • Founded 2007
  3. 3
    Environmental Science Associates· San Francisco, California, United States
    • 744 employees
    • Founded 1969
  4. 4
    AMS· San Francisco, California, United States
    • 633 employees
    • Founded 2013
  5. 5
    Bay Area Air District· San Francisco, California, United States
    • Grant
    • 459 employees
    • Founded 1955
  6. 6
    Environmental Services· San Francisco, California, United States
    • 432 employees
    • Founded 1993
  7. 7
    Golden Gate National Parks Conservancy· San Francisco, California, United States
    • 343 employees
    • Founded 1981
  8. 8
    3Degrees Group, Inc.· San Francisco, California, United States
    • Series unknown
    • 320 employees
    • Founded 2007
  9. 9
    Plus Power· San Francisco, California, United States
    • undisclosed
    • 261 employees
    • Founded 2018
  10. 10
    California Coastal Commission· San Francisco, California, United States
    • 188 employees
    • Founded 1972
  11. 11
    Heirloom· San Francisco, California, United States
    • undisclosed
    • 174 employees
    • Founded 2020
  12. 12
    SunLink· San Francisco, California, United States
    • Debt
    • 125 employees
    • Founded 2004
  13. 13
    San Francisco Environment Department· San Francisco, California, United States
    • 120 employees
    • Founded 1996
  14. 14
    BRIGHTMARK· San Francisco, California, United States
    • 98 employees
    • Founded 2016
  15. 15
    Otherlab· San Francisco, Minnesota, United States
    • Grant
    • 96 employees
    • Founded 2009
  16. 16
    Charm Industrial· San Francisco, California, United States
    • Series B
    • 95 employees
    • Founded 2018
  17. 17
    Patch· San Francisco, California, United States
    • Series B
    • 94 employees
    • Founded 2020
  18. 18
    Terradot· San Francisco, California, United States
    • non equity assistance
    • 93 employees
    • Founded 2022
  19. 19
    San Francisco Conservation Corps· San Francisco, California, United States
    • 89 employees
    • Founded 1983
  20. 20
    Ecoplexus Inc.· San Francisco, California, United States
    • Debt
    • 83 employees
    • Founded 2010
  21. 21
    San Francisco Bay Conservation and Development Commission (BCDC)· San Francisco, California, United States
    • 78 employees
    • Founded 1965
  22. 22
    NCX· San Francisco, California, United States
    • Series B
    • 75 employees
    • Founded 2010
  23. 23
    BurnBot· South San Francisco, California, United States
    • Series A
    • 70 employees
    • Founded 2022
  24. 24
    Women in Cleantech and Sustainability· San Francisco, California, United States
    • 64 employees
    • Founded 2010
  25. 25
    SINAI Carbon Management· San Francisco, California, United States
    • Series unknown
    • 58 employees
    • Founded 2017

Find engineers at Climate tech companies in San Francisco

San Francisco has long been a hub for Climate tech, and the list above ranks the largest Climate tech companies headquartered there by current headcount, drawn from public LinkedIn and Crunchbase records. With 101 matching companies in our index, this is a good map of where the Climate tech talent in San Franciscolives — useful whether you’re recruiting, partnering, or sizing a market.

The biggest Climate tech companies in San Francisco tend to be the gravitational centres for specialised talent — senior engineers, ML researchers, applied scientists, designers — while the smaller ones compete on speed, equity, and proximity to founders.

Refolk converts this list into a live search. Ask for “Climate tech engineers in San Franciscohiring senior staff” or “founders of Climate tech companies in San Franciscowho left in the last 12 months” and Refolk returns a ranked shortlist with the evidence that earned each person a spot.

How this list is built

Refolk pulled Climate tech companies headquartered in San Francisco from public LinkedIn and Crunchbase records, ranked them by current employee count, and kept those with at least 10 employees. The list refreshes once a day.

Last refreshed: Thu, 07 May 2026 08:21:29 GMT

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