Company lists · Data refreshed September 2026

Top 25 Energy and sustainability consultants based in the United States

Name: Energy and sustainability consultants based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 3,956 companies tracked

RevenueBase identified 3,956 energy and sustainability consultants headquartered in the United States as of September 2026 and tracks 67,867 professional contacts across them, including 31,787 with verified work emails. New York is the largest hub.

This list covers energy and sustainability consultants 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 21, 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 21, 2026 86% judged on-target in blind review

3,956Companies

67,867Contacts tracked

31,787Verified emails

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The 25 largest energy and sustainability consultants based in the United States

Ranked by team size

Top 25 of 3,956 energy and sustainability consultants based in the United States, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to energy and sustainability consultants: 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	FTI	Partial evidence	Menasha, WI, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,741 contacts →
	Partial evidence “Faith Technologies Incorporated (FTI) is a dynamic organization comprised of construction, engineering, manufacturing and renewable energy experts.” Source: RevenueBase Database · checked Sep 21, 2026
2	Mckinstry	Partial evidence	Seattle, WA, United StatesHQ checked Sep 21, 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 21, 2026
3	Langan Engineering & Environmental Services	Indirect evidence	Parsippany, NJ, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,177 contacts →
	Indirect evidence “Langan's client-focused, highly entrepreneurial culture cultivates an environment of opportunities in which career growth and teamwork flourish.” Source: RevenueBase Database · checked Sep 21, 2026
4	Clearesult	Strong evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,121 contacts →
	Strong evidence “CLEAResult is the largest provider of energy efficiency, energy transition and energy sustainability services in North America.” Source: RevenueBase Database · checked Sep 21, 2026
5	Westwood Professional Services	Indirect evidence	Plano, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,661 contacts →
	Indirect evidence “At Westwood, our purpose is to create a better world for people through our work.” Source: RevenueBase Database · checked Sep 21, 2026
6	Swca Environmental Consultants	Indirect evidence	Phoenix, AZ, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,629 contacts →
	Indirect evidence “Founded on a commitment to sound science and creative solutions, SWCA is a leader in environmental and management consulting services.” Source: RevenueBase Database · checked Sep 21, 2026
7	Ameresco	Partial evidence	Framingham, MA, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,383 contacts →
	Partial 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 21, 2026
8	OLA	Partial evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	n/a	1,145 contacts →
	Partial evidence “OLA Sustainability, LLC OLA Sustainability is a consulting firm that focuses on integrating sustainable practices into commercial and multifamily design projects.” Source: RevenueBase Database · checked Sep 21, 2026
9	World Kinect	Partial evidence	Miami, FL, United StatesHQ checked Sep 21, 2026	1,001-5,000	998 contacts →
	Partial evidence “Headquartered in Miami, Florida, World Kinect Corporation (NYSE: WKC) is a leading global energy management company, offering a broad suite of solutions across the energy product…” Source: RevenueBase Database · checked Sep 21, 2026
10	Willdan	Indirect evidence	Anaheim, CA, United StatesHQ checked Sep 21, 2026	1,001-5,000	851 contacts →
	Indirect evidence “Willdan (NASDAQ: WLDN) provides professional consulting and technical services to utilities, public agencies and private industry throughout the United States.” Source: RevenueBase Database · checked Sep 21, 2026
11	Franklin Energy	Strong evidence	Port Washington, WI, United StatesHQ checked Sep 21, 2026	1,001-5,000	838 contacts →
	Strong evidence “Franklin Energy delivers end-to-end sustainability solutions through a portfolio of intelligent products and services that lower energy costs, reduce carbon and waste, and grow…” Source: RevenueBase Database · checked Sep 21, 2026
12	Energy Solutions	Partial evidence	Oakland, CA, United StatesHQ checked Sep 21, 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 21, 2026
13	PAE	Partial evidence	Portland, OR, United StatesHQ checked Sep 21, 2026	201-500	744 contacts →
	Partial evidence “PAE provides mechanical and electrical engineering design, technology system design, energy modeling and analysis, and more.” Source: RevenueBase Database · checked Sep 21, 2026
14	Resource Innovations	Partial evidence	Half Moon Bay, CA, United StatesHQ checked Sep 21, 2026	501-1,000	733 contacts →
	Partial evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 21, 2026
15	Antea Group USA	Indirect evidence	St Paul, MN, United StatesHQ checked Sep 21, 2026	1,001-5,000	658 contacts →
	Indirect evidence “Antea Group is an international engineering and environmental consulting firm specializing in full-service solutions in the fields of environment, health and safety, and…” Source: RevenueBase Database · checked Sep 21, 2026
16	Noresco	Partial evidence	Westborough, MA, United StatesHQ checked Sep 21, 2026	201-500	481 contacts →
	Partial evidence “NORESCO, a part of Carrier Global Corporation, helps customers modernize aging building systems and upgrade energy and water infrastructure to meet evolving demands.” Source: RevenueBase Database · checked Sep 21, 2026
17	Dupont Water Solutions	Indirect evidence	Wilmington, DE, United StatesHQ checked Sep 21, 2026	10001+	470 contacts →
	Indirect evidence “We’re helping companies in every industry, in every corner of the globe make real progress.” Source: RevenueBase Database · checked Sep 21, 2026
18	Sitelogiq	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 21, 2026	501-1,000	450 contacts →
	Indirect evidence “SitelogIQ provides design, engineering, and construction management services that help organizations nationwide modernize their facilities and infrastructure.” Source: RevenueBase Database · checked Sep 21, 2026
19	Veregy	Partial evidence	Phoenix, MO, United StatesHQ checked Sep 21, 2026	501-1,000	383 contacts →
	Partial evidence “Veregy is an award-winning NAESCO-Accredited decarbonization company focusing on accelerating and simplifying the Energy Transition.” Source: RevenueBase Database · checked Sep 21, 2026
20	TRIO	Partial evidence	Irvine, CA, United StatesHQ checked Sep 21, 2026	201-500	383 contacts →
	Partial evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 21, 2026
21	Energyscape Renewables	Indirect evidence	Denver, United StatesHQ checked Sep 21, 2026	501-1,000	379 contacts →
	Indirect evidence “Established in 2019.” Source: RevenueBase Database · checked Sep 21, 2026
22	P2s	Indirect evidence	Long Beach, CA, United StatesHQ checked Sep 21, 2026	201-500	375 contacts →
	Indirect evidence “P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.” Source: RevenueBase Database · checked Sep 21, 2026
23	Wendel Companies	Partial evidence	Williamsville, NY, United StatesHQ checked Sep 21, 2026	201-500	355 contacts →
	Partial evidence “Wendel is an Architecture, Engineering, Energy Efficiency, and Construction Management Firm that delivers customized solutions and turnkey projects in innovative ways.” Source: RevenueBase Database · checked Sep 21, 2026
24	NUS Consulting Group	Indirect evidence	Park Ridge, NJ, United StatesHQ checked Sep 21, 2026	201-500	336 contacts →
	Indirect evidence “National Utility Service, Inc.” Source: RevenueBase Database · checked Sep 21, 2026
25	Customized Energy Solutions	Partial evidence	Philadelphia, PA, United StatesHQ checked Sep 21, 2026	201-500	330 contacts →
	Partial evidence “Customized Energy Solutions is at the forefront of competitive energy markets.” Source: RevenueBase Database · checked Sep 21, 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: energy and sustainability consultants. 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 energy and sustainability consultants.
Partial evidence: Its own public description names part of energy and sustainability consultants, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name energy and sustainability consultants. 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 3,956 energy and sustainability consultants based in the United States

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Energy and sustainability consultants based in the United States at a glance

As of Sep 21, 2026

46.8%Verified-email coverage

17.2Average contacts per company

1-10Median size (employees)

4.3%Largest-city concentration · New York

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

2,403

11-50

1,109

51-200

310

201-500

501-1,000

1,001-5,000

5,001-10,000

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 3,956 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 energy and sustainability consultants, 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 “energy and sustainability consultants”. 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 energy and sustainability consultants), 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 energy and sustainability consultants, 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, 31,787 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 21, 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.

Energy and sustainability consultants 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 energy and sustainability consultants, 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 energy and sustainability consultants are there based in the United States?

RevenueBase identified 3,956 energy and sustainability consultants 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?

FTI, headquartered in Menasha, tops this list with the largest team on record.

Which city has the most energy and sustainability consultants?

New York leads with 172 headquartered companies, followed by Houston (170) and Chicago (90).

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 31,787 verified decision-maker contacts tracked across these 3,956 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 21, 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.