Company lists · Data refreshed September 2026

Top 25 Clean energy consultants worldwide

Name: Clean energy consultants worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 22,995 companies tracked

RevenueBase identified 22,995 clean energy consultants worldwide as of September 2026 and tracks 362,638 professional contacts across them, including 123,329 with verified work emails and 0 with mobile numbers. The United States is the largest market and London the largest hub.

This list covers clean energy consultants worldwide, 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 16, 2026. Country and city lists for clean energy consultants follow the table.

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 16, 2026 86% judged on-target in blind review

22,995Companies

362,638Contacts tracked

123,329Verified emails

0Mobile numbers

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The 25 largest clean energy consultants worldwide

Ranked by team size

Top 25 of 22,995 clean energy consultants worldwide, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to clean energy consultants: 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	Worley	Partial evidence	Sydney, AustraliaHQ checked Sep 16, 2026	10001+	34,763 contacts →
	Partial evidence “Worley is a global professional services company of energy, chemicals and resources experts headquartered in Australia.” Source: RevenueBase Database · checked Sep 16, 2026
2	Stantec	Indirect evidence	Edmonton, AB, CanadaHQ checked Sep 16, 2026	10001+	28,416 contacts →
	Indirect evidence “Stantec empowers clients, people, and communities to rise to the world’s greatest challenges at a time when the world faces more unprecedented concerns than ever before.” Source: RevenueBase Database · checked Sep 16, 2026
3	WOOD	Partial evidence	Aberdeen, United KingdomHQ checked Sep 16, 2026	10001+	26,949 contacts →
	Partial evidence “Wood is a global leader in consulting and engineering, delivering critical solutions across energy and materials markets.” Source: RevenueBase Database · checked Sep 16, 2026
4	ERM	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	5,001-10,000	9,119 contacts →
	Indirect evidence “Sustainability is our business.” Source: RevenueBase Database · checked Sep 16, 2026
5	Dalkia	Indirect evidence	Saint-andré-lez-lille, FranceHQ checked Sep 16, 2026	10001+	8,427 contacts →
	Indirect evidence “Dalkia : ensemble, relevons le défi climatique!” Source: RevenueBase Database · checked Sep 16, 2026
6	SLR Consulting	Indirect evidence	London, United KingdomHQ checked Sep 16, 2026	1,001-5,000	3,848 contacts →
	Indirect evidence “SLR is a committed partner in our clients’ sustainability journeys.” Source: RevenueBase Database · checked Sep 16, 2026
7	FTI	Partial evidence	Menasha, WI, United StatesHQ checked Sep 16, 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 16, 2026
8	Langan Engineering & Environmental Services	Indirect evidence	Parsippany, NJ, United StatesHQ checked Sep 16, 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 16, 2026
9	Clearesult	Partial evidence	Austin, TX, United StatesHQ checked Sep 16, 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 16, 2026
10	Westwood Professional Services	Indirect evidence	Plano, TX, United StatesHQ checked Sep 16, 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 16, 2026
11	Vulcain Engineering Group	Partial evidence	Neuilly-sur-seine, FranceHQ checked Sep 16, 2026	5,001-10,000	1,496 contacts →
	Partial evidence “Vulcain Engineering Group is a multi-specialist engineering and consulting group serving industrial companies across the globe, focused on critical sectors: energy, health…” Source: RevenueBase Database · checked Sep 16, 2026
12	Ameresco	Partial evidence	Framingham, MA, United StatesHQ checked Sep 16, 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 16, 2026
13	IPE Global Limited	Indirect evidence	New Delhi, IndiaHQ checked Sep 16, 2026	501-1,000	1,322 contacts →
	Indirect evidence “Headquartered in India with six international offices in Cambodia, Ethiopia, Kenya, the Philippines, Germany and the United Kingdom, IPE Global Group offers a range of integrated…” Source: RevenueBase Database · checked Sep 16, 2026
14	Fichtner	Strong evidence	Stuttgart, GermanyHQ checked Sep 16, 2026	1,001-5,000	1,279 contacts →
	Strong evidence “As a leading, independent engineering and consultancy enterprise active in the sectors of energy and infrastructure, Fichtner handles challenging projects in countries all over…” Source: RevenueBase Database · checked Sep 16, 2026
15	Grupo Cosampa	Partial evidence	Fortaleza, BrazilHQ checked Sep 16, 2026	1,001-5,000	1,245 contacts →
	Partial evidence “O Grupo Cosampa vem conquistando espaço no mercado, através da prestação de serviços com qualidade e excelência, nas áreas de construção civil, engenharia elétrica e energias…” Source: RevenueBase Database · checked Sep 16, 2026
16	OLA	Indirect evidence	Austin, TX, United StatesHQ checked Sep 16, 2026	n/a	1,145 contacts →
	Indirect 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 16, 2026
17	Barr Engineering CO	Indirect evidence	Minneapolis, MN, United StatesHQ checked Sep 16, 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 16, 2026
18	Penspen	Partial evidence	London, United KingdomHQ checked Sep 16, 2026	1,001-5,000	1,007 contacts →
	Partial evidence “Penspen designs, maintains, and optimises energy infrastructure to improve access to secure and sustainable energy for communities worldwide.” Source: RevenueBase Database · checked Sep 16, 2026
19	Wanzek Construction, Inc., A Mastec Company	Strong evidence	Fargo, ND, United StatesHQ checked Sep 16, 2026	1,001-5,000	933 contacts →
	Strong evidence “Wanzek Construction, Inc, a MasTec Renewables company, is a leading general construction contractor and clean energy services company headquartered in Fargo, North Dakota.” Source: RevenueBase Database · checked Sep 16, 2026
20	Willdan	Indirect evidence	Anaheim, CA, United StatesHQ checked Sep 16, 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 16, 2026
21	Juwi Group	Partial evidence	Wörrstadt, GermanyHQ checked Sep 16, 2026	1,001-5,000	785 contacts →
	Partial evidence “For 30 years, we have been one of the leading specialists in renewable energies, offering complete project development and other services related to the planning, construction…” Source: RevenueBase Database · checked Sep 16, 2026
22	Energy Solutions	Partial evidence	Oakland, CA, United StatesHQ checked Sep 16, 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 16, 2026
23	NWG S.P.A	Indirect evidence	Prato, ItalyHQ checked Sep 16, 2026	n/a	766 contacts →
	Indirect evidence “Nata a Prato nel 2003 è oggi una delle più importanti realtà nel mercato della Green Economy.” Source: RevenueBase Database · checked Sep 16, 2026
24	Cleanmax	Partial evidence	Mumbai, IndiaHQ checked Sep 16, 2026	201-500	735 contacts →
	Partial evidence “CleanMax is India’s largest commercial and industrial (“C&I”) renewable energy provider with 3 GW of operational, owned and managed capacity.” Source: RevenueBase Database · checked Sep 16, 2026
25	Resource Innovations	Partial evidence	Half Moon Bay, CA, United StatesHQ checked Sep 16, 2026	501-1,000	733 contacts →
	Partial evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 16, 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: clean energy consultants. 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 clean energy consultants.
Partial evidence: Its own public description names part of clean energy consultants, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name clean energy consultants. 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 22,995 clean energy consultants worldwide

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Clean energy consultants worldwide at a glance

As of Sep 16, 2026

34.0%Verified-email coverage

15.8Average contacts per company

1-10Median size (employees)

1.5%Largest-city concentration · London

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

13,872

11-50

6,938

51-200

1,560

201-500

320

501-1,000

1,001-5,000

5,001-10,000

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 clean energy consultants, 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.
Coverage: 55 countries, largest first: the United States, Brazil, France, the United Kingdom, Spain, Germany, Italy, India, the Netherlands, Australia and 45 more. Country and city lists for clean energy consultants are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “clean energy consultants”. 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 clean energy consultants), 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 clean energy consultants, and records with no verified work email.
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, 123,329 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 16, 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.

Clean energy consultants by location

123 lists · largest first

Every Clean energy consultants list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 clean energy consultants, 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 clean energy consultants are there worldwide?

RevenueBase identified 22,995 clean energy consultants worldwide 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?

Worley, headquartered in Sydney, tops this list with the largest team on record.

Which country has the most clean energy consultants?

The United States leads with 3,383 companies, followed by Brazil (2,011) and France (1,551). Every clean energy consultants list by country and city is linked on this page.

Which city has the most clean energy consultants?

London leads with 353 headquartered companies, followed by Madrid (273) and Paris (253).

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 123,329 verified decision-maker contacts tracked across these 22,995 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 16, 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.