Company lists · Data refreshed September 2026

Top 25 Energy consulting firms based in the United States

Name: Energy consulting firms based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 2, 2026 3,927 companies tracked

RevenueBase identified 3,927 energy consulting firms headquartered in the United States as of September 2026 and tracks 74,853 professional contacts across them, including 33,265 with verified work emails and 33,416 with mobile numbers. Houston is the largest hub.

This list covers energy consulting firms 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 2, 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 RevenueBase Smart Search rating on every row Refreshed Sep 2, 2026 86% judged on-target in blind review

3,927Companies

74,853Contacts tracked

33,265Verified emails

33,416Mobile numbers

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest energy consulting firms based in the United States

Ranked by team size

Top 25 of 3,927 energy consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 2, 2026. RevenueBase Smart Search rates how each company's information relates to energy consulting firms: 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	Midland, TX, United States	1,001-5,000	4,145 contacts →
	Indirect evidence “Sargent & Lundy is one of the world’s longest-standing full-service architect engineering firms.” Source: RevenueBase Database · checked Sep 2, 2026
2	FTI	Partial evidence	Menasha, WI, United States	1,001-5,000	2,712 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 2, 2026
3	Mckinstry	Partial evidence	Scottsdale, AZ, United States	1,001-5,000	2,198 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 2, 2026
4	Langan Engineering & Environmental Services	Indirect evidence	El Segundo, CA, United States	1,001-5,000	2,136 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 2, 2026
5	Westwood Professional Services	Indirect evidence	Lake Charles, LA, United States	1,001-5,000	1,631 contacts →
	Indirect evidence “At Westwood, our purpose is to create a better world for people through our work.” Source: RevenueBase Database · checked Sep 2, 2026
6	Swca Environmental Consultants	Partial evidence	Phoenix, AZ, United States	1,001-5,000	1,618 contacts →
	Partial 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 2, 2026
7	Ameresco	Partial evidence	Framingham, MA, United States	1,001-5,000	1,475 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 2, 2026
8	Partner Engineering & Science, INC	Indirect evidence	Pasadena, CA, United States	1,001-5,000	1,348 contacts →
	Indirect evidence “Partner Assessment Corp.” Source: RevenueBase Database · checked Sep 2, 2026
9	Barr Engineering CO	Partial evidence	Washington, United States	1,001-5,000	1,098 contacts →
	Partial 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 2, 2026
10	Willdan	Partial evidence	Anaheim, CA, United States	1,001-5,000	838 contacts →
	Partial 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 2, 2026
11	Resource Innovations	Partial evidence	Chandler, AZ, United States	501-1,000	724 contacts →
	Partial evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 2, 2026
12	Capco Energy	Strong evidence	Houston, TX, United States	1,001-5,000	711 contacts →
	Strong 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 2, 2026
13	Inerco	Indirect evidence	Delaware, United States	1,001-5,000	682 contacts →
	Indirect evidence “INERCO, with 30 years of experience, offers comprehensive services and develops advanced technologies that contribute to sustainable industrial development, acting as a leader in…” Source: RevenueBase Database · checked Sep 2, 2026
14	Applied Consultants	Indirect evidence	Longview, TX, United States	501-1,000	580 contacts →
	Indirect evidence “Since 1991, Applied Consultants Inc.” Source: RevenueBase Database · checked Sep 2, 2026
15	Natural Power	Partial evidence	Seattle, WA, United States	501-1,000	505 contacts →
	Partial evidence “Natural Power is a leading independent consultancy and service provider for the renewable energy sector.” Source: RevenueBase Database · checked Sep 2, 2026
16	Hunt Guillot & Associates HGA	Partial evidence	Ruston, LA, United States	501-1,000	499 contacts →
	Partial 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 2, 2026
17	Sitelogiq	Indirect evidence	Minneapolis, MN, United States	501-1,000	451 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 2, 2026
18	Takkion	Partial evidence	Evansville, WY, United States	1,001-5,000	360 contacts →
	Partial evidence “TAKKION is Moving Energy Forward.” Source: RevenueBase Database · checked Sep 2, 2026
19	Meraki Solar	Indirect evidence	Dallas, TX, United States	1,001-5,000	274 contacts →
	Indirect evidence “People.” Source: RevenueBase Database · checked Sep 2, 2026
20	Direct Energy Business	Partial evidence	Pittsburgh, PA, United States	1,001-5,000	252 contacts →
	Partial evidence “Direct Energy Business is part of a leading energy and energy-related services provider that is focused on helping customers make their businesses better.” Source: RevenueBase Database · checked Sep 2, 2026
21	Nuverra Environmental Solutions	Indirect evidence	Scottsdale, AZ, United States	501-1,000	201 contacts →
	Indirect evidence “Nuverra Environmental Solutions is a company dedicated to the protection, enhancement and advancement of environmental solutions.” Source: RevenueBase Database · checked Sep 2, 2026
22	Power Grid Engineering, LLC	Partial evidence	Lake Mary, FL, United States	1,001-5,000	160 contacts →
	Partial evidence “Qualus is a leading pure-play power services firm and innovator at the forefront of the energy transition and transformation, with differentiated capabilities across grid…” Source: RevenueBase Database · checked Sep 2, 2026
23	Morrison Energy	Partial evidence	Houma, LA, United States	501-1,000	139 contacts →
	Partial evidence “Morrison, an energy service company, delivers infrastructure projects to clients in the oil and gas and renewables industries.” Source: RevenueBase Database · checked Sep 2, 2026
24	Seam Group	Partial evidence	Beachwood, OH, United States	10001+	130 contacts →
	Partial evidence “ABB has finalized the acquisition of SEAM Group, a US-based provider of energized asset management and advisory services to clients across industrial and commercial building…” Source: RevenueBase Database · checked Sep 2, 2026
25	Synergy Companies	Partial evidence	Fresno, CA, United States	501-1,000	124 contacts →
	Partial evidence “Synergy Companies is the largest energy services companies in California and provides a comprehensive approach to energy efficiency and environmental solutions in both the…” Source: RevenueBase Database · checked Sep 2, 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 consulting firms. 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 consulting firms.
Partial evidence: Its own public description names part of energy consulting firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name energy consulting firms. 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 3,927 energy consulting firms based in the United States

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 33,265 reachable decision-makers.

Free signup · no credit card

View the full list →

Energy consulting firms based in the United States at a glance

As of Sep 2, 2026

44.4%Verified-email coverage

44.6%Mobile-number coverage

19.1Average contacts per company

1-10Median size (employees)

5.6%Largest-city concentration · Houston

Sep 2, 2026Page data refreshed

Companies by employee count

1-10

2,238

11-50

1,197

51-200

336

201-500

501-1,000

1,001-5,000

10001+

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 consulting firms, 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 consulting firms”. 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 consulting firms), 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 consulting firms, 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, 33,265 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 2, 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 consulting firms 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 consulting firms, 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 consulting firms are there based in the United States?

RevenueBase identified 3,927 energy consulting firms 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 Midland, tops this list with the largest team on record.

Which city has the most energy consulting firms?

Houston leads with 221 headquartered companies, followed by New York (127) and Denver (65).

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 33,265 verified decision-maker contacts tracked across these 3,927 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 2, 2026.

Ready to reach these companies? Verified emails and direct dials for all 3,927 energy consulting firms based in the United States. Start with a free account, no credit card.

Download this list →

Related lists

Energy consulting firms by geography

Browse the directory

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.