Company lists · Data refreshed September 2026

Top 25 Renewable energy consultancy companies based in the United States

RevenueBase identified 2,669 renewable energy consultancy companies headquartered in the United States as of September 2026 and tracks 39,672 professional contacts across them, including 17,714 with verified work emails and 16,928 with mobile numbers. Houston is the largest hub.

This list covers renewable energy consultancy companies 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, how directly it supports the match, and when it was last checked. Data refreshed September 5, 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 HQ checked on every row Match evidence on every row Refreshed Sep 5, 2026 86% judged on-target in blind review
2,669Companies
39,672Contacts tracked
17,714Verified emails
16,928Mobile numbers
Explore all 2,669 companies → Free signup · no credit card · 500 free credits

The 25 largest renewable energy consultancy companies based in the United States

Ranked by team size
Top 25 of 2,669 renewable energy consultancy companies based in the United States, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names renewable energy consultancy companies: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
FTIStrong evidence
Menasha, WI, United StatesHQ checked Sep 5, 20261,001-5,0002,741

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

Source: company website · checked Sep 5, 2026
2Plano, TX, United StatesHQ checked Sep 5, 20261,001-5,0001,661

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

Source: company website · checked Sep 5, 2026
3Torrance, CA, United StatesHQ checked Sep 5, 20261,001-5,0001,358

“Partner Assessment Corp.”

Source: company website · checked Sep 5, 2026
4
Barr Engineering COIndirect evidence
Minneapolis, MN, United StatesHQ checked Sep 5, 20261,001-5,0001,088

“Barr provides engineering and environmental consulting services to clients across the Midwest, throughout the Americas, and around the world.”

Source: company website · checked Sep 5, 2026
5Fargo, ND, United StatesHQ checked Sep 5, 20261,001-5,000933

“Wanzek Construction, Inc, a MasTec Renewables company, is a leading general construction contractor and clean energy services company headquartered in Fargo, North Dakota.”

Source: company website · checked Sep 5, 2026
6
WilldanIndirect evidence
Anaheim, CA, United StatesHQ checked Sep 5, 20261,001-5,000851

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

Source: company website · checked Sep 5, 2026
7
Resource InnovationsPartial evidence
Half Moon Bay, CA, United StatesHQ checked Sep 5, 2026501-1,000733

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

Source: company website · checked Sep 5, 2026
8
Synergy Consulting, INCIndirect evidence
Washington, DC, United StatesHQ checked Sep 5, 202651-200434

“Synergy Consulting is Global Leader in Financial and Corporate Advisory.”

Source: company website · checked Sep 5, 2026
9
TRIOPartial evidence
Irvine, CA, United StatesHQ checked Sep 5, 2026201-500383

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

Source: company website · checked Sep 5, 2026
10
P2sIndirect evidence
Long Beach, CA, United StatesHQ checked Sep 5, 2026201-500375

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

Source: company website · checked Sep 5, 2026
11
TakkionPartial evidence
Evansville, WY, United StatesHQ checked Sep 5, 20261,001-5,000358

“TAKKION is Moving Energy Forward.”

Source: company website · checked Sep 5, 2026
12
NUS Consulting GroupIndirect evidence
Park Ridge, NJ, United StatesHQ checked Sep 5, 2026201-500336

“National Utility Service, Inc.”

Source: company website · checked Sep 5, 2026
13Lakewood, CO, United StatesHQ checked Sep 5, 2026201-500318

“NEI provides professional expertise and design engineering services for all aspects of power systems engineering.”

Source: company website · checked Sep 5, 2026
14Gainesville, FL, United StatesHQ checked Sep 5, 2026201-500305

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

Source: company website · checked Sep 5, 2026
15Jackson, MI, United StatesHQ checked Sep 5, 2026201-500305

“We provide expert engineering and consulting services that enable a more reliable and resilient power system.”

Source: company website · checked Sep 5, 2026
16
Csrs, A Westwood CompanyIndirect evidence
Baton Rouge, LA, United StatesHQ checked Sep 5, 202651-200305

“CSRS was acquired by Westwood Professional Services on June 30, 2025.”

Source: company website · checked Sep 5, 2026
17
Cascade EnergyPartial evidence
Portland, OR, United StatesHQ checked Sep 5, 2026201-500288

“At Cascade Energy, we believe in better.”

Source: company website · checked Sep 5, 2026
18
Lake Superior ConsultingPartial evidence
Duluth, MN, United StatesHQ checked Sep 5, 2026201-500281

“We act as an extension of your team, combining deep energy expertise with seamless alignment to your processes to advance projects with confidence.”

Source: company website · checked Sep 5, 2026
19
Illumine-IIndirect evidence
Austin, CA, United StatesHQ checked Sep 5, 2026201-500275

“The world runs on power.”

Source: company website · checked Sep 5, 2026
20Valhalla, NY, United StatesHQ checked Sep 5, 2026201-500268

“Con Edison Clean Energy Businesses, Inc.(Con Edison CEB) is a leader in the renewable energy industry.”

Source: company website · checked Sep 5, 2026
21
MerjentPartial evidence
Minneapolis, MN, United StatesHQ checked Sep 5, 2026201-500264

“Merjent is an environmental, restoration, and engineering consulting firm with a long history serving the energy industry.”

Source: company website · checked Sep 5, 2026
22
Nova Group, GBCPartial evidence
St. Louis Park, MN, United StatesHQ checked Sep 5, 2026201-500264

“Nova Group, GBC is an international, multidisciplinary advising firm providing environmental, engineering and energy services throughout North America and around the globe.”

Source: company website · checked Sep 5, 2026
23
PSC ConsultingStrong evidence
Kirkland, WA, United StatesHQ checked Sep 5, 2026201-500254

“We provide global renewable energy consulting services, focused on empowering clients to navigate the complexities of the energy transition.”

Source: company website · checked Sep 5, 2026
24
Baywa R.E. AmericasStrong evidence
Carlsbad, CA, United StatesHQ checked Sep 5, 2026201-500244

“rethinkenergy BayWa r.e is a leading global renewable energy company committed to delivering best-in-class projects, services and solutions.”

Source: company website · checked Sep 5, 2026
25
Kleinschmidt AssociatesPartial evidence
Pittsfield, ME, United StatesHQ checked Sep 5, 2026201-500218

“At Kleinschmidt, we work primarily with energy companies and government agencies in North America to protect and enhance the environment without compromising performance.”

Source: company website · checked Sep 5, 2026

Showing 25 of 2,669 renewable energy consultancy companies based in the United States

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Renewable energy consultancy companies based in the United States at a glance

As of Sep 5, 2026
1-10Median size (employees)
HoustonLargest hub · 115 HQs
16,928Contacts with mobile numbers
Sep 5, 2026Data refreshed

Companies by employee count

1-10
1,563
11-50
779
51-200
233
201-500
49
501-1,000
14
1,001-5,000
22
5,001-10,000
1
10001+
2

Verified emails by last verification

0–30
16,584
31–60
1,055
61–90
4
90–180
9
180+
62

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 renewable energy consultancy companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence 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 SmartSearch, 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 “renewable energy consultancy companies”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among renewable energy consultancy companies, 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 an evidence 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, 17,714 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 5, 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.

Frequently asked

How many renewable energy consultancy companies are there based in the United States?

RevenueBase identified 2,669 renewable energy consultancy companies 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 renewable energy consultancy companies?

Houston leads with 115 headquartered companies, followed by New York (83) and Denver (53).

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 17,714 verified decision-maker contacts tracked across these 2,669 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 5, 2026.

Ready to reach these companies? Verified emails and direct dials for all 2,669 renewable energy consultancy companies based in the United States. Start with a free account, no credit card.

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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.