Company lists · Data refreshed August 2026

Top 25 Clean energy consulting firms based in the United States

RevenueBase identified 4,875 company matches for clean energy consulting firms associated with the United States as of August 2026 and tracks 70,161 professional contacts across them, including 29,539 with verified work emails and 29,278 with mobile numbers. Houston is the largest hub.

This list covers company matches for clean energy consulting firms associated with the United States, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed August 31, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 SmartSearch · Exact Recorded Aug 31, 2026 How this list was built
4,875Companies
70,161Contacts tracked
29,539Verified emails
29,278Mobile numbers
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The 25 largest clean energy consulting firms based in the United States

Ranked by team size
Top 25 of 4,875 company matches for clean energy consulting firms based in the United States, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Aug 31, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchMidland, TX, United States1,001-5,0004,145 contacts →

Exact match

“Sargent & Lundy is one of the world’s longest-standing full-service architect engineering firms.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
2Exact matchMenasha, WI, United States1,001-5,0002,712 contacts →

Exact match

“Faith Technologies Incorporated (FTI) is a dynamic organization comprised of construction, engineering, manufacturing and renewable energy experts.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
3Exact matchScottsdale, AZ, United States1,001-5,0002,198 contacts →

Exact match

“We're a national construction and energy services company dedicated to innovating the waste and climate harm out of the built environment.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
4Exact matchLake Charles, LA, United States1,001-5,0001,631 contacts →

Exact match

“At Westwood, our purpose is to create a better world for people through our work.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
5Exact matchFramingham, MA, United States1,001-5,0001,475 contacts →

Exact match

“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…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
6Exact matchAnaheim, CA, United States1,001-5,000838 contacts →

Exact match

“Willdan (NASDAQ: WLDN) provides professional consulting and technical services to utilities, public agencies and private industry throughout the United States.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
7Exact matchOrange, CA, United States201-500768 contacts →

Exact match

“Our mission is simple - to combat climate change through market-based, cost-effective energy, carbon, and water management solutions that make big impacts.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
8Exact matchChandler, AZ, United States501-1,000724 contacts →

Exact match

“Resource Innovations (RI) is an energy transformation firm.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
9Exact matchHouston, TX, United States1,001-5,000711 contacts →

Exact match

“For 25 years Capco’s Energy practice has combined innovative thinking with deep industry knowledge to provide business consulting, digital transformation and technology services…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
10Exact matchDelaware, United States1,001-5,000682 contacts →

Exact match

“INERCO, with 30 years of experience, offers comprehensive services and develops advanced technologies that contribute to sustainable industrial development, acting as a leader in…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
11Exact matchBedminster, NJ, United States1,001-5,000623 contacts →

Exact match

“DEPCOM Power, a Koch Engineered Solutions Company, is a leading solar energy solutions partner providing Development Support, Engineering, Procurement & Construction (EPC)…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
12Exact matchBoston, MA, United States201-500527 contacts →

Exact match

“As a global energy consultancy, we unite our unique and diverse people to share knowledge, innovate and inspire change within the energy industry.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
13Exact matchSeattle, WA, United States501-1,000505 contacts →

Exact match

“Natural Power is a leading independent consultancy and service provider for the renewable energy sector.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
14Exact matchWilmington, DE, United States10001+472 contacts →

Exact match

“We’re helping companies in every industry, in every corner of the globe make real progress.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
15Exact matchMclean, VA, United States201-500382 contacts →

Exact match

“We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
16Exact matchPhoenix, AZ, United States501-1,000376 contacts →

Exact match

“Veregy is an award-winning NAESCO-Accredited decarbonization company focusing on accelerating and simplifying the Energy Transition.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
17Exact matchDenver, United States501-1,000376 contacts →

Exact match

“Established in 2019.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
18Exact matchFort Worth, TX, United States201-500373 contacts →

Exact match

“Manhard Consulting has joined Atwell, a national consulting, engineering, and construction services firm with 2,100 technical professionals across the country.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
19Exact matchIrvine, CA, United States201-500370 contacts →

Exact match

“P2S has brought forward-thinking, sustainable engineering solutions to California, the Pacific Northwest, and beyond, for over 30 years.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
20Exact matchEvansville, WY, United States1,001-5,000360 contacts →

Exact match

“TAKKION is Moving Energy Forward.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
21Exact matchMiddletown, CT, United States201-500354 contacts →

Exact match

“Wendel is an Architecture, Engineering, Energy Efficiency, and Construction Management Firm that delivers customized solutions and turnkey projects in innovative ways.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
22Exact matchBoston, MA, United States201-500335 contacts →

Exact match

“Customized Energy Solutions is at the forefront of competitive energy markets.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
23Exact matchHouston, TX, United States1,001-5,000327 contacts →

Exact match

“U.S.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
24Exact matchSan Francisco, CA, United States201-500325 contacts →

Exact match

“3Degrees is a leading global climate solutions provider, pioneer of environmental markets, and Certified B Corporation.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
25Exact matchTampa, FL, United States201-500303 contacts →

Exact match

“Environmental Consulting & Technology, Inc.(ECT) is a multi-disciplinary environmental and sustainability consulting firm delivering strategy, permitting, design, and management…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase

Showing 25 of 4,875 clean energy consulting firms based in the United States

See the full list, filter by size, metro and specialty, and access 29,539 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Clean energy consulting firms based in the United States at a glance

As of Aug 31, 2026
42.1%Verified-email coverage
41.7%Mobile-number coverage
14.4Average contacts per company
1-10Median size (employees)
4.6%Largest-city concentration · Houston
Aug 31, 2026Page data refreshed

Companies by employee count

1-10
3,005
11-50
1,333
51-200
382
201-500
81
501-1,000
21
1,001-5,000
32
10001+
3

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United States whose business descriptions match “clean energy consulting firms” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 29,539 professional contacts with verified work emails across the full matched dataset. 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 August 31, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “clean energy consulting firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many clean energy consulting firms are there based in the United States?

RevenueBase identified 4,875 company matches for clean energy consulting firms associated with the United States as of August 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Sargent & Lundy tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most clean energy consulting firms?

Houston leads with 223 company records, followed by New York (194) and Denver (96).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 29,539 professional contacts with verified work emails tracked across these 4,875 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on August 31, 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 SmartSearch, 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.