Company lists · Data refreshed September 2026

Top 25 Energy consultancies based in the United States

Name: Energy consultancies 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 4,249 companies tracked

RevenueBase identified 4,249 energy consultancies headquartered in the United States as of September 2026 and tracks 80,633 professional contacts across them, including 35,096 with verified work emails. Houston is the largest hub.

This list covers energy consultancies 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

4,249Companies

80,633Contacts tracked

35,096Verified emails

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The 25 largest energy consultancies based in the United States

Ranked by team size

Top 25 of 4,249 energy consultancies 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 consultancies: 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	Sargent & Lundy	Indirect evidence	Chicago, WY, United StatesHQ checked Sep 21, 2026	1,001-5,000	4,156 contacts →
	Indirect evidence “Sargent & Lundy is one of the world’s longest-standing full-service architect engineering firms.” Source: RevenueBase Database · checked Sep 21, 2026
2	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
3	APTIM	Indirect evidence	Baton Rouge, LA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,639 contacts →
	Indirect evidence “APTIM enhances the quality of the environment, wellbeing of people, resilience of communities, and opportunity for employees to make a difference, not just a living.” Source: RevenueBase Database · checked Sep 21, 2026
4	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
5	Clearesult	Partial evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,121 contacts →
	Partial 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
6	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
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	Barr Engineering CO	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 21, 2026	1,001-5,000	1,088 contacts →
	Indirect evidence “Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.” 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	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
12	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
13	Capco Energy	Partial evidence	Houston, TX, United StatesHQ checked Sep 21, 2026	1,001-5,000	715 contacts →
	Partial evidence “For 25 years Capco’s Energy practice has combined innovative thinking with deep industry knowledge to provide business consulting, digital transformation and technology services…” Source: RevenueBase Database · checked Sep 21, 2026
14	Electric Power Engineers	Indirect evidence	Austin, TX, United StatesHQ checked Sep 21, 2026	501-1,000	630 contacts →
	Indirect evidence “Electric Power Engineers (EPE) is a global advisory and engineering firm advancing grid reliability, resilience, flexibility, and affordability.” Source: RevenueBase Database · checked Sep 21, 2026
15	Applied Consultants	Indirect evidence	Longview, TX, United StatesHQ checked Sep 21, 2026	501-1,000	578 contacts →
	Indirect evidence “Since 1991, Applied Consultants Inc.” Source: RevenueBase Database · checked Sep 21, 2026
16	Hunt Guillot & Associates HGA	Indirect evidence	Ruston, LA, United StatesHQ checked Sep 21, 2026	501-1,000	505 contacts →
	Indirect evidence “HGA is a leading engineering, consulting, and program management company that has been delivering innovative and sustainable solutions to our clients for over 29 years.” Source: RevenueBase Database · checked Sep 21, 2026
17	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
18	Babcock Power	Indirect evidence	Danvers, MA, United StatesHQ checked Sep 21, 2026	501-1,000	476 contacts →
	Indirect evidence “Finding a single capable partner to support both large- and small-scale power generation needs can be challenging.” Source: RevenueBase Database · checked Sep 21, 2026
19	Calpine Energy Solutions, LLC	Partial evidence	San Diego, CA, United StatesHQ checked Sep 21, 2026	201-500	467 contacts →
	Partial evidence “Calpine Solutions is a retail energy provider with a robust suite of customized products, analytics, and data management solutions to turn a corporate electricity expense into a…” 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	E Source	Partial evidence	Houston, TX, United StatesHQ checked Sep 21, 2026	201-500	377 contacts →
	Partial evidence “For decades, E Source has been a trusted partner to utilities navigating an evolving energy landscape.” 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	Takkion	Partial evidence	Evansville, WY, United StatesHQ checked Sep 21, 2026	1,001-5,000	358 contacts →
	Partial evidence “TAKKION is Moving Energy Forward.” Source: RevenueBase Database · checked Sep 21, 2026
24	IHI E&c International Corporation	Partial evidence	Houston, TX, United StatesHQ checked Sep 21, 2026	n/a	356 contacts →
	Partial evidence “Now IHI Energy Solutions, Inc, visit our page” Source: RevenueBase Database · checked Sep 21, 2026
25	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

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 consultancies. 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 consultancies.
Partial evidence: Its own public description names part of energy consultancies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name energy consultancies. 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 4,249 energy consultancies based in the United States

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Energy consultancies based in the United States at a glance

As of Sep 21, 2026

43.5%Verified-email coverage

19.0Average contacts per company

1-10Median size (employees)

6.2%Largest-city concentration · Houston

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

2,462

11-50

1,254

51-200

367

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 4,249 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 consultancies, 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 consultancies”. 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 consultancies), 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 consultancies, 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, 35,096 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 consultancies 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 consultancies, 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 consultancies are there based in the United States?

RevenueBase identified 4,249 energy consultancies 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?

Sargent & Lundy, headquartered in Casper, tops this list with the largest team on record.

Which city has the most energy consultancies?

Houston leads with 265 headquartered companies, followed by New York (154) and Dallas (73).

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 35,096 verified decision-maker contacts tracked across these 4,249 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.