Company lists · Data refreshed September 2026
Top 25 Climate tech accelerators based in the United States
RevenueBase identified 217 climate tech accelerators headquartered in the United States as of September 2026 and tracks 2,117 professional contacts across them, including 791 with verified work emails. New York is the largest hub.
This list covers climate tech accelerators headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 19, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.
The 25 largest climate tech accelerators based in the United States
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 149 contacts → | ||||
Partial evidence “The Massachusetts Clean Energy Center is a state economic development agency dedicated to accelerating the growth of the clean energy and climatetech sector across the…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 136 contacts → | ||||
Strong evidence “New Energy Nexus (NEX) is the world's leading ecosystem of funds and accelerators supporting diverse clean energy entrepreneurs to thrive, from emerging tech through to clean…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 132 contacts → | ||||
Partial evidence “The Cleantech Open runs the world's largest cleantech accelerator.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 94 contacts → | ||||
Partial evidence “Greentown Labs is a 501(c)(3) nonprofit accelerating climatetech innovation for the planet, people, and prosperity.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 80 contacts → | ||||
Indirect evidence “Syzygy Plasmonics is a technology company decarbonizing chemical production with its proprietary light-driven reactor technology.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 79 contacts → | ||||
Indirect evidence “Infinium is reimagining how the world powers, moves, and computes.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 58 contacts → | ||||
Indirect evidence “We work with entrepreneurs to refine ideas, attract talent, access capital, and accelerate growth.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 57 contacts → | ||||
Indirect evidence “Decarbonizing the World's Legacy Buildings Kelvin’s technology reduces wasted energy, saves money, and enables pinpoint temperature control for apartments in legacy buildings.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 54 contacts → | ||||
Strong evidence “Sealed is a climate tech company on a mission to stop home energy waste by enabling contractors to install more home weatherization and electrification projects and grow their…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 54 contacts → | ||||
Indirect evidence “Clean Energy Ventures is a venture capital firm focused on investing in companies commercializing disruptive advanced energy technologies and business model innovations that can…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 37 contacts → | ||||
Strong evidence “Partnered with MIT and Greentown Labs, our mission is to train and develop the next generation of energy transition and climate tech entrepreneurs from some of the leading Texas…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 34 contacts → | ||||
Indirect evidence “BRITE is an innovation-first ecosystem advancing the clean energy economy.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 27 contacts → | ||||
Strong evidence “At G2 Venture Partners, we’ve been investing in climate-tech for over 15 years, seeking out and partnering with companies at their inflection point that are changing how the world…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 25 contacts → | ||||
Partial evidence “MCJ is an early-stage fund for the energy and industry transition and the inevitable impacts of climate change.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 22 contacts → | ||||
Partial evidence “The Radicle Development Center is a new approach to building out and scaling up solutions in the ClimateTech & HardTech space.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 20 contacts → | ||||
Strong evidence “ClimateHaven is a climate tech incubator for world-class innovators and entrepreneurs.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 19 contacts → | ||||
Indirect evidence “Factor E was founded in 2013, to accelerate the impact of innovation on economies, communities, and the environment.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 18 contacts → | ||||
Partial evidence “Capital for Climate (C4C) is accelerating capital deployment to climate solutions required to achieve a 1.5°C degree outcome.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 17 contacts → | ||||
Partial evidence “Evergreen Climate Innovations, formerly Clean Energy Trust, provides catalytic capital and support to entrepreneurs and startups that bring impactful climate technologies to…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 17 contacts → | ||||
Strong evidence “Joules is a non-profit organization that supports early-stage climate tech startups in the Southeast and beyond.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 15 contacts → | ||||
Partial evidence “Prelude Ventures invests in and supports early-stage startups with the greatest potential to mitigate climate change.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 15 contacts → | ||||
Indirect evidence “ETCH’s revolutionary decarbonization technology delivers unrivaled economic value and versatility that will accelerate the clean energy transition.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 15 contacts → | ||||
Strong evidence “Thalo Labs: Climate Tech for the World We Live In” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 15 contacts → | ||||
Partial evidence “CleanLeap is on a journey to champion sustainable innovation, partnering with ClimateLaunchpad as its representative in the USA.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 15 contacts → | ||||
Partial evidence “Halliburton Labs is an energy venture catalyst that collaborates with hard-tech ventures to propel their journey from innovation to industrial scale.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: climate tech accelerators. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names climate tech accelerators.
- Partial evidence
- Its own public description names part of climate tech accelerators, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name climate tech accelerators. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 217 climate tech accelerators based in the United States
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Climate tech accelerators based in the United States at a glance
As of Sep 19, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 217 companies.
How this list was built
Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among climate tech accelerators, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
- What qualifies
- Companies headquartered in the United States whose own description of what they do matches “climate tech accelerators”. Matching reads each company's description, not its industry code or its name.
- RevenueBase Smart Search
- RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names climate tech accelerators), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
- What we exclude
- Companies whose own description does not clearly place them among climate tech accelerators, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
- Match quality
- In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
- Ranking
- Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
- Verification
- Every listed company carries at least one verified work email, 791 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
- Refresh
- This page's figures were pulled from the company graph on September 19, 2026. Lists refresh periodically as the graph is re-checked.
- Corrections
- Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.
Frequently asked
What is RevenueBase Smart Search?
RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names climate tech accelerators, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.
How many climate tech accelerators are there based in the United States?
RevenueBase identified 217 climate tech accelerators headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.
What is the largest company on this list?
Massachusetts Clean Energy Center, headquartered in Boston, tops this list with the largest team on record.
Which city has the most climate tech accelerators?
New York leads with 24 headquartered companies, followed by San Francisco (20) and Houston (12).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 791 verified decision-maker contacts tracked across these 217 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 2026.
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About this data
RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.
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