Company lists · Data refreshed September 2026

Top 25 Clean energy consultancies worldwide

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

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 37,222 companies tracked

RevenueBase identified 37,222 clean energy consultancies worldwide as of September 2026 and tracks 473,307 professional contacts across them, including 154,169 with verified work emails. The United States is the largest market and London the largest hub.

This list covers clean energy consultancies 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 21, 2026. Country and city lists for clean energy consultancies 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 21, 2026 86% judged on-target in blind review

37,222Companies

473,307Contacts tracked

154,169Verified emails

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The 25 largest clean energy consultancies worldwide

Ranked by team size

Top 25 of 37,222 clean energy consultancies worldwide, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to clean energy consultancies: 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 21, 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 21, 2026
2	Stantec	Indirect evidence	Edmonton, AB, CanadaHQ checked Sep 21, 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 21, 2026
3	WOOD	Partial evidence	Aberdeen, United KingdomHQ checked Sep 21, 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 21, 2026
4	ERM	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	5,001-10,000	9,119 contacts →
	Indirect evidence “Sustainability is our business.” Source: RevenueBase Database · checked Sep 21, 2026
5	Dalkia	Indirect evidence	Saint-andré-lez-lille, FranceHQ checked Sep 21, 2026	10001+	8,427 contacts →
	Indirect evidence “Dalkia : ensemble, relevons le défi climatique!” Source: RevenueBase Database · checked Sep 21, 2026
6	Roland Berger	Indirect evidence	Munich, GermanyHQ checked Sep 21, 2026	1,001-5,000	4,632 contacts →
	Indirect evidence “Roland Berger is the only leading global strategy consultancy of European origin.” Source: RevenueBase Database · checked Sep 21, 2026
7	RENEW	Strong evidence	Gurugram, IndiaHQ checked Sep 21, 2026	1,001-5,000	4,340 contacts →
	Strong evidence “ReNew is a leading decarbonisation solutions provider and the first Indian clean energy company to list on Nasdaq (Nasdaq: RNW).” Source: RevenueBase Database · checked Sep 21, 2026
8	Sargent & Lundy	Indirect evidence	Chicago, WY, United StatesHQ checked Sep 21, 2026	1,001-5,000	4,156 contacts →
	Indirect evidence “Sargent & Lundy is one of the world’s longest-standing full-service architect engineering firms.” Source: RevenueBase Database · checked Sep 21, 2026
9	SLR Consulting	Indirect evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
10	FTI	Partial evidence	Menasha, WI, United StatesHQ checked Sep 21, 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 21, 2026
11	WSP I Sverige	Indirect evidence	Stockholm-marievik, SwedenHQ checked Sep 21, 2026	10001+	2,607 contacts →
	Indirect evidence “What if you could shape built and natural environments – and the future of those that use them?” Source: RevenueBase Database · checked Sep 21, 2026
12	Mckinstry	Partial evidence	Seattle, WA, United StatesHQ checked Sep 21, 2026	1,001-5,000	2,213 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 21, 2026
13	Clearesult	Partial evidence	Austin, TX, United StatesHQ checked Sep 21, 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 21, 2026
14	Baycurrent	Indirect evidence	港区, JapanHQ checked Sep 21, 2026	5,001-10,000	1,900 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 21, 2026
15	Westwood Professional Services	Indirect evidence	Plano, TX, United StatesHQ checked Sep 21, 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 21, 2026
16	Steag Energy Services India Pvt. LTD	Partial evidence	Noida, IndiaHQ checked Sep 21, 2026	1,001-5,000	1,572 contacts →
	Partial evidence “STEAG Energy Services India, established in 2001 as a wholly owned subsidiary of STEAG GmbH, Germany, is now part of the Bluspring Enterprises Limited, India’s integrated…” Source: RevenueBase Database · checked Sep 21, 2026
17	Vulcain Engineering Group	Partial evidence	Neuilly-sur-seine, FranceHQ checked Sep 21, 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 21, 2026
18	Ameresco	Partial evidence	Framingham, MA, United StatesHQ checked Sep 21, 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 21, 2026
19	IPE Global Limited	Indirect evidence	New Delhi, IndiaHQ checked Sep 21, 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 21, 2026
20	Fichtner	Partial evidence	Stuttgart, GermanyHQ checked Sep 21, 2026	1,001-5,000	1,279 contacts →
	Partial 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 21, 2026
21	OLA	Indirect evidence	Austin, TX, United StatesHQ checked Sep 21, 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 21, 2026
22	Gruppo AB	Partial evidence	Orzinuovi, United KingdomHQ checked Sep 21, 2026	1,001-5,000	1,081 contacts →
	Partial evidence “Since 1981, AB has tackled the challenges posed by energy sustainability, working alongside our customers to improve their competitiveness while saving energy and reducing…” Source: RevenueBase Database · checked Sep 21, 2026
23	Penspen	Partial evidence	London, United KingdomHQ checked Sep 21, 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 21, 2026
24	Anthesis Group	Indirect evidence	London, United KingdomHQ checked Sep 21, 2026	1,001-5,000	894 contacts →
	Indirect evidence “Anthesis guides clients to sustainable performance.” Source: RevenueBase Database · checked Sep 21, 2026
25	BPA	Indirect evidence	Montréal, QC, CanadaHQ checked Sep 21, 2026	1,001-5,000	882 contacts →
	Indirect evidence “IMPACTFUL ENGINEERING At BPA, it’s simple: we are building experts.” Source: RevenueBase Database · checked Sep 21, 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 consultancies. 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 consultancies.
Partial evidence: Its own public description names part of clean energy consultancies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name clean energy consultancies. 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 37,222 clean energy consultancies worldwide

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Clean energy consultancies worldwide at a glance

As of Sep 21, 2026

32.6%Verified-email coverage

12.7Average contacts per company

1-10Median size (employees)

1.6%Largest-city concentration · London

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

23,684

11-50

10,332

51-200

2,278

201-500

482

501-1,000

133

1,001-5,000

127

5,001-10,000

10001+

Email recency is reported on each country list linked below.

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 consultancies, 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: Every country. Country and city lists for clean energy consultancies are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “clean energy consultancies”. 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 consultancies), 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 consultancies, 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, 154,169 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 21, 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 consultancies by location

151 lists · largest first

Every Clean energy consultancies 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 consultancies, 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 consultancies are there worldwide?

RevenueBase identified 37,222 clean energy consultancies 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 consultancies?

The United States leads with 4,102 companies, followed by the United Kingdom (2,524) and Brazil (2,347). Every clean energy consultancies list by country and city is linked on this page.

Which city has the most clean energy consultancies?

London leads with 607 headquartered companies, followed by Paris (356) and Madrid (352).

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 154,169 verified decision-maker contacts tracked across these 37,222 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 21, 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.