Company lists · Data refreshed September 2026

Top 25 Energy auditing and consulting firms based in the United States

Name: Energy auditing and 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 28, 2026 2,390 companies tracked

RevenueBase identified 2,390 energy auditing and consulting firms headquartered in the United States as of September 2026 and tracks 35,827 professional contacts across them, including 15,715 with verified work emails. New York is the largest hub.

This list covers energy auditing and 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 28, 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 28, 2026 86% judged on-target in blind review

2,390Companies

35,827Contacts tracked

15,715Verified emails

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

The 25 largest energy auditing and consulting firms based in the United States

Ranked by team size

Top 25 of 2,390 energy auditing and consulting firms based in the United States, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to energy auditing and 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	Clearesult	Partial evidence	Austin, TX, United StatesHQ checked Sep 28, 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 28, 2026
2	Ameresco	Partial evidence	Framingham, MA, United StatesHQ checked Sep 28, 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 28, 2026
3	OLA	Partial evidence	Austin, TX, United StatesHQ checked Sep 28, 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 28, 2026
4	Willdan	Partial evidence	Anaheim, CA, United StatesHQ checked Sep 28, 2026	1,001-5,000	851 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 28, 2026
5	Syska Hennessy Group	Indirect evidence	New York, United StatesHQ checked Sep 28, 2026	501-1,000	803 contacts →
	Indirect evidence “Consult Engineer Commission At Syska Hennessy Group, we create exceptional environments.” Source: RevenueBase Database · checked Sep 28, 2026
6	EBI Consulting	Indirect evidence	Burlington, MA, United StatesHQ checked Sep 28, 2026	501-1,000	535 contacts →
	Indirect evidence “For 35 years we have been helping investors, lenders, owners, developers, contractors, and property managers reduce risk and optimize their built facilities, infrastructure and…” Source: RevenueBase Database · checked Sep 28, 2026
7	TRIO	Partial evidence	Irvine, CA, United StatesHQ checked Sep 28, 2026	201-500	383 contacts →
	Partial evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 28, 2026
8	P2s	Indirect evidence	Long Beach, CA, United StatesHQ checked Sep 28, 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 28, 2026
9	Wendel Companies	Partial evidence	Williamsville, NY, United StatesHQ checked Sep 28, 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 28, 2026
10	NUS Consulting Group	Indirect evidence	Park Ridge, NJ, United StatesHQ checked Sep 28, 2026	201-500	336 contacts →
	Indirect evidence “National Utility Service, Inc.” Source: RevenueBase Database · checked Sep 28, 2026
11	Cascade Energy	Partial evidence	Portland, OR, United StatesHQ checked Sep 28, 2026	201-500	288 contacts →
	Partial evidence “At Cascade Energy, we believe in better.” Source: RevenueBase Database · checked Sep 28, 2026
12	PSC Consulting	Strong evidence	Kirkland, WA, United StatesHQ checked Sep 28, 2026	201-500	254 contacts →
	Strong evidence “We provide global renewable energy consulting services, focused on empowering clients to navigate the complexities of the energy transition.” Source: RevenueBase Database · checked Sep 28, 2026
13	CMC Energy Services	Partial evidence	Fort Washington, PA, United StatesHQ checked Sep 28, 2026	201-500	252 contacts →
	Partial evidence “CMC Energy Services is a woman-owned full-service energy efficiency company with nearly 50 years of experience delivering value-based energy conservation services.” Source: RevenueBase Database · checked Sep 28, 2026
14	Mantis Innovation	Partial evidence	Houston, TX, United StatesHQ checked Sep 28, 2026	201-500	233 contacts →
	Partial evidence “At Mantis Innovation, our experts provide data-driven, consultative services designed to optimize your facility, sustainability, and energy management strategies, while ultimately…” Source: RevenueBase Database · checked Sep 28, 2026
15	Allana Buick & Bers, INC	Partial evidence	Palo Alto, CA, United StatesHQ checked Sep 28, 2026	201-500	229 contacts →
	Partial evidence “Allana Buick & Bers, Inc.(ABB) is a leading Architectural Engineering firm specializing in making buildings perform better by making them energy efficient and longer lasting with…” Source: RevenueBase Database · checked Sep 28, 2026
16	Walker-Miller Energy Services	Partial evidence	Detroit, MI, United StatesHQ checked Sep 28, 2026	51-200	216 contacts →
	Partial evidence “Walker-Miller Energy Services (Walker-Miller), one of the largest African American and woman owned energy efficiency companies in the United States, changes lives through energy.” Source: RevenueBase Database · checked Sep 28, 2026
17	PEG	Partial evidence	Fairfax, VA, United StatesHQ checked Sep 28, 2026	201-500	214 contacts →
	Partial evidence “PEG presents a comprehensive capacity for the evaluation and understanding of a broad base of energy and environmental sustainability related programs, policies and initiatives.” Source: RevenueBase Database · checked Sep 28, 2026
18	Dalkia Energy Solutions	Partial evidence	Beverly, MA, United StatesHQ checked Sep 28, 2026	201-500	210 contacts →
	Partial 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 28, 2026
19	Bright Power	Partial evidence	New York, NY, United StatesHQ checked Sep 28, 2026	51-200	205 contacts →
	Partial evidence “Bright Power is a leading provider of energy efficiency and decarbonization solutions for the real estate industry.” Source: RevenueBase Database · checked Sep 28, 2026
20	Energy Management Collaborative EMC	Partial evidence	Minneapolis, MN, United StatesHQ checked Sep 28, 2026	201-500	193 contacts →
	Partial evidence “EMC manages and scales turnkey energy efficiency solutions for Fortune 500 clients across their North American portfolios.” Source: RevenueBase Database · checked Sep 28, 2026
21	Frontier Energy, INC	Partial evidence	Pleasanton, CA, United StatesHQ checked Sep 28, 2026	51-200	192 contacts →
	Partial evidence “Frontier Energy is a professional services firm that excels in market transformation.” Source: RevenueBase Database · checked Sep 28, 2026
22	Cenergistic	Partial evidence	Dallas, TX, United StatesHQ checked Sep 28, 2026	201-500	190 contacts →
	Partial evidence “At Cenergistic, energy conservation starts with people.” Source: RevenueBase Database · checked Sep 28, 2026
23	Hargis Engineers	Strong evidence	Seattle, WA, United StatesHQ checked Sep 28, 2026	201-500	188 contacts →
	Strong evidence “Hargis Engineers is a mechanical, electrical, telecommunications, security, energy consulting engineering, and commissioning firm.” Source: RevenueBase Database · checked Sep 28, 2026
24	Nexant	Strong evidence	Half Moon Bay, CA, United StatesHQ checked Sep 28, 2026	201-500	183 contacts →
	Strong evidence “Resource Innovations now combined with Nexant is a substantially woman-owned, woman-led energy consulting firm dedicated to creating equal access to clean resources through…” Source: RevenueBase Database · checked Sep 28, 2026
25	Thielsch Engineering	Indirect evidence	Cranston, RI, United StatesHQ checked Sep 28, 2026	501-1,000	175 contacts →
	Indirect evidence “Thielsch, Inc.” Source: RevenueBase Database · checked Sep 28, 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 auditing and 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 auditing and consulting firms.
Partial evidence: Its own public description names part of energy auditing and 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 auditing and 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 2,390 energy auditing and 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 15,715 reachable decision-makers.

Free signup · no credit card

View the full list →

Energy auditing and consulting firms based in the United States at a glance

As of Sep 28, 2026

43.9%Verified-email coverage

15.0Average contacts per company

1-10Median size (employees)

4.1%Largest-city concentration · New York

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

1,358

11-50

781

51-200

188

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 2,390 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 auditing and 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 auditing and 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 auditing and 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 auditing and 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, 15,715 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 28, 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 auditing and 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 auditing and 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 auditing and consulting firms are there based in the United States?

RevenueBase identified 2,390 energy auditing and 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?

Clearesult, headquartered in Austin, tops this list with the largest team on record.

Which city has the most energy auditing and consulting firms?

New York leads with 99 headquartered companies, followed by Houston (77) and Chicago (37).

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 15,715 verified decision-maker contacts tracked across these 2,390 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 28, 2026.

Ready to reach these companies? Verified emails and direct dials for all 2,390 energy auditing and consulting firms based in the United States. Start with a free account, no credit card.

Download this list →

Related lists

Energy auditing and 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.