Company lists · Data refreshed September 2026

Top 25 Climate tech startups based in the United States

Name: Climate tech startups based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 745 companies tracked

RevenueBase identified 745 climate tech startups headquartered in the United States as of September 2026 and tracks 38,808 professional contacts across them, including 16,878 with verified work emails. New York is the largest hub.

This list covers climate tech startups 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 19, 2026 86% judged on-target in blind review

745Companies

38,808Contacts tracked

16,878Verified emails

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The 25 largest climate tech startups based in the United States

Ranked by team size

Top 25 of 745 climate tech startups based in the United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to climate tech startups: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Trane Technologies	Partial evidence	Davidson, NC, United StatesHQ checked Sep 19, 2026	10001+	12,878 contacts →
	Partial evidence “Trane Technologies is a global climate innovator advancing sustainability through our leading brands Trane® and Thermo King®, which bring efficient and sustainable climate…” Source: RevenueBase Database · checked Sep 19, 2026
2	Carrier	Partial evidence	Palm Beach Gardens, FL, United StatesHQ checked Sep 19, 2026	10001+	7,665 contacts →
	Partial evidence “Carrier is a global leader in intelligent climate and energy solutions, pioneering sustainable innovations in climate technologies.” Source: RevenueBase Database · checked Sep 19, 2026
3	Mckinstry	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1,001-5,000	2,213 contacts →
	Partial evidence “We're a national construction and energy services company dedicated to innovating the waste and climate harm out of the built environment.” Source: RevenueBase Database · checked Sep 19, 2026
4	Clearesult	Indirect evidence	Austin, TX, United StatesHQ checked Sep 19, 2026	1,001-5,000	2,121 contacts →
	Indirect evidence “CLEAResult is the largest provider of energy efficiency, energy transition and energy sustainability services in North America.” Source: RevenueBase Database · checked Sep 19, 2026
5	Ameresco	Indirect evidence	Framingham, MA, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,383 contacts →
	Indirect evidence “Ameresco, Inc.(NYSE:AMRC) is a leading energy infrastructure solutions provider dedicated to helping customers reduce costs, enhance resilience, and decarbonize to net zero in the…” Source: RevenueBase Database · checked Sep 19, 2026
6	California Resources Corporation	Indirect evidence	Los Angeles, CA, United StatesHQ checked Sep 19, 2026	1,001-5,000	1,095 contacts →
	Indirect evidence “California Resources Corporation (CRC) is an independent energy and carbon management company committed to energy transition.” Source: RevenueBase Database · checked Sep 19, 2026
7	Energy Solutions	Partial evidence	Oakland, CA, United StatesHQ checked Sep 19, 2026	201-500	772 contacts →
	Partial evidence “Our mission is simple - to combat climate change through market-based, cost-effective energy, carbon, and water management solutions that make big impacts.” Source: RevenueBase Database · checked Sep 19, 2026
8	Resource Innovations	Indirect evidence	Half Moon Bay, CA, United StatesHQ checked Sep 19, 2026	501-1,000	733 contacts →
	Indirect evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 19, 2026
9	GTI Energy	Indirect evidence	Des Plaines, IL, United StatesHQ checked Sep 19, 2026	201-500	513 contacts →
	Indirect evidence “For more than eight decades, GTI Energy has contributed to the strengthening of energy systems and the communities they serve.” Source: RevenueBase Database · checked Sep 19, 2026
10	Veregy	Indirect evidence	Phoenix, MO, United StatesHQ checked Sep 19, 2026	501-1,000	383 contacts →
	Indirect evidence “Veregy is an award-winning NAESCO-Accredited decarbonization company focusing on accelerating and simplifying the Energy Transition.” Source: RevenueBase Database · checked Sep 19, 2026
11	VEIC	Indirect evidence	Winooski, VT, United StatesHQ checked Sep 19, 2026	201-500	326 contacts →
	Indirect evidence “For 40 years, VEIC has helped energy leaders nationwide meet their clean energy goals.” Source: RevenueBase Database · checked Sep 19, 2026
12	3degrees Group, INC	Partial evidence	San Francisco, CA, United StatesHQ checked Sep 19, 2026	201-500	324 contacts →
	Partial evidence “3Degrees is a leading global climate solutions provider, pioneer of environmental markets, and Certified B Corporation.” Source: RevenueBase Database · checked Sep 19, 2026
13	Cimarron	Indirect evidence	Houston, TX, United StatesHQ checked Sep 19, 2026	501-1,000	306 contacts →
	Indirect evidence “With decades of operating history and innovation across our trusted brands, Cimarron provides technology-driven emissions management solutions for the global energy system.” Source: RevenueBase Database · checked Sep 19, 2026
14	Energy & Environmental Research Center	Indirect evidence	Grand Forks, ND, United StatesHQ checked Sep 19, 2026	201-500	213 contacts →
	Indirect evidence “The Energy & Environmental Research Center (EERC) is recognized as one of the world's leading developers of cleaner, more efficient energy to power the world and environmental…” Source: RevenueBase Database · checked Sep 19, 2026
15	Dalkia Energy Solutions	Indirect evidence	Beverly, MA, United StatesHQ checked Sep 19, 2026	201-500	210 contacts →
	Indirect evidence “Dalkia Energy Solutions, a subsidiary of the EDF (Électricité de France) Group, is a national leader in energy efficiency and sustainability for commercial, industrial, and…” Source: RevenueBase Database · checked Sep 19, 2026
16	Anew Climate	Partial evidence	Houston, TX, United StatesHQ checked Sep 19, 2026	201-500	200 contacts →
	Partial evidence “Anew Climate is a global leader of diverse climate solutions, bringing innovative products and services to the public and private sectors to help reduce or offset their carbon…” Source: RevenueBase Database · checked Sep 19, 2026
17	Carbon Direct	Partial evidence	New York, United StatesHQ checked Sep 19, 2026	51-200	172 contacts →
	Partial evidence “Carbon Direct is a trusted energy and climate solutions company that combines world-class scientific expertise, technical rigor, and market insights to help clients achieve their…” Source: RevenueBase Database · checked Sep 19, 2026
18	Clean AIR Task Force	Indirect evidence	Boston, MA, United StatesHQ checked Sep 19, 2026	51-200	167 contacts →
	Indirect evidence “CATF advocates for the change in technologies and policies needed to get to a zero-emissions, high-energy planet at an affordable cost.” Source: RevenueBase Database · checked Sep 19, 2026
19	Breakthrough Energy	Indirect evidence	Kirkland, United StatesHQ checked Sep 19, 2026	51-200	159 contacts →
	Indirect evidence “Breakthrough Energy backs companies developing the next generation of clean energy solutions.” Source: RevenueBase Database · checked Sep 19, 2026
20	Cleanchoice Energy	Partial evidence	Washington, DC, United StatesHQ checked Sep 19, 2026	51-200	155 contacts →
	Partial evidence “CleanChoice Energy is a cleantech company that empowers people and businesses to easily access climate solutions.” Source: RevenueBase Database · checked Sep 19, 2026
21	Slipstream	Indirect evidence	Madison, WI, United StatesHQ checked Sep 19, 2026	51-200	146 contacts →
	Indirect evidence “We're a nonprofit headquartered in Madison, WI with an office in Chicago and remote staff across the U.S.” Source: RevenueBase Database · checked Sep 19, 2026
22	Seaboard Energy	Indirect evidence	Merriam, KS, United StatesHQ checked Sep 19, 2026	201-500	142 contacts →
	Indirect evidence “Seaboard Energy, a Seaboard Corporation business, is dedicated to finding alternative energy sources.” Source: RevenueBase Database · checked Sep 19, 2026
23	Luminace	Indirect evidence	New York, NY, United StatesHQ checked Sep 19, 2026	51-200	126 contacts →
	Indirect evidence “Luminace is one of the largest fully integrated decarbonization-as-a-service solution providers in North America, sponsoring accessible, reliable and renewable energy…” Source: RevenueBase Database · checked Sep 19, 2026
24	Climeco	Indirect evidence	Houston, TX, United StatesHQ checked Sep 19, 2026	51-200	96 contacts →
	Indirect evidence “ClimeCo is an award-winning leader in decarbonization, empowering global organizations with customized sustainability pathways.” Source: RevenueBase Database · checked Sep 19, 2026
25	E'kabel	Indirect evidence	Houston, TX, United StatesHQ checked Sep 19, 2026	51-200	96 contacts →
	Indirect evidence “At E’kabel, we design and implement solutions that drive efficiency, sustainability, and performance across energy operations.” Source: RevenueBase Database · checked Sep 19, 2026

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 startups. 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 startups.
Partial evidence: Its own public description names part of climate tech startups, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name climate tech startups. 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 745 climate tech startups based in the United States

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Climate tech startups based in the United States at a glance

As of Sep 19, 2026

43.5%Verified-email coverage

52.1Average contacts per company

1-10Median size (employees)

6.8%Largest-city concentration · New York

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

466

11-50

191

51-200

201-500

501-1,000

1,001-5,000

10001+

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 745 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 startups, 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 startups”. 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 startups), 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 startups, 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, 16,878 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.

Climate tech startups by metro

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 startups, 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 startups are there based in the United States?

RevenueBase identified 745 climate tech startups 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?

Trane Technologies, headquartered in Davidson, tops this list with the largest team on record.

Which city has the most climate tech startups?

New York leads with 51 headquartered companies, followed by Houston (45) and San Francisco (39).

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 16,878 verified decision-maker contacts tracked across these 745 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.