Company lists · Data refreshed September 2026
Top 25 Energy efficiency consulting firms worldwide
RevenueBase identified 11,412 energy efficiency consulting firms worldwide as of September 2026 and tracks 126,755 professional contacts across them, including 43,986 with verified work emails and 18,783 with mobile numbers. The United States is the largest market and Madrid the largest hub.
This list covers energy efficiency consulting firms 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 2, 2026. Country and city lists for energy efficiency consulting firms 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.
The 25 largest energy efficiency consulting firms worldwide
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 9,287 contacts → | ||||
Indirect evidence “Taking care of things.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 2 | 8,459 contacts → | ||||
Indirect evidence “Dalkia : ensemble, relevons le défi climatique!” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 3 | 4,058 contacts → | ||||
Partial evidence “Enova is the regional leader in integrated energy and multi-technical services, delivering comprehensive services to its clients.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 4 | 2,137 contacts → | ||||
Strong evidence “CLEAResult is the largest provider of energy efficiency, energy transition and energy sustainability services in North America.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 5 | 1,475 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 2, 2026Thanks. The Data Team will review it. | |||||
| 6 | 1,149 contacts → | ||||
Indirect evidence “GK er en ledende teknisk entreprenør og servicepartner.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 7 | 838 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 2, 2026Thanks. The Data Team will review it. | |||||
| 8 | 806 contacts → | ||||
Indirect evidence “Consult Engineer Commission At Syska Hennessy Group, we create exceptional environments.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 9 | 724 contacts → | ||||
Partial evidence “Resource Innovations (RI) is an energy transformation firm.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 10 | 685 contacts → | ||||
Partial evidence “Albireo Energy is a leading independent building controls and energy services provider recognized by customers for creating intelligent, high-performance buildings.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 11 | 484 contacts → | ||||
Partial evidence “NORESCO, a part of Carrier Global Corporation, helps customers modernize aging building systems and upgrade energy and water infrastructure to meet evolving demands.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 12 | 469 contacts → | ||||
Partial evidence “Veolia Industries Global Solutions est devenu Veolia Energie Performance depuis le 1er juin 2025.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 13 | 451 contacts → | ||||
Indirect evidence “SitelogIQ provides design, engineering, and construction management services that help organizations nationwide modernize their facilities and infrastructure.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 14 | 400 contacts → | ||||
Partial evidence “Since 2009, GreenFlex has been a key partner in the energy, environmental and societal transformation of organizations, enabling them to change their trajectory towards an economy…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 15 | 382 contacts → | ||||
Partial evidence “We are Trio – built from Edison Energy, Alfa Energy, and Altenex Energy.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 16 | 370 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 2, 2026Thanks. The Data Team will review it. | |||||
| 17 | 355 contacts → | ||||
Strong evidence “Since 1964 the MCW Group has built a solid reputation for the delivery of Professional Consulting Engineering Services, Energy Management Services, and Engineering Development…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 18 | 354 contacts → | ||||
Strong 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 2, 2026Thanks. The Data Team will review it. | |||||
| 19 | 342 contacts → | ||||
Partial evidence “The National Energy Services Company (TARSHID) is a national company wholly owned by the Public Investment Fund (PIF).” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 20 | 334 contacts → | ||||
Indirect evidence “National Utility Service, Inc.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 21 | 321 contacts → | ||||
Indirect evidence “As environmental design consultants, building services engineers and lighting designers, we are committed to high performance and sustainable design within the built environment.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 22 | 315 contacts → | ||||
Partial evidence “EIC Partnership: A Legacy of Expertise, A Commitment to Sustainability With origins dating back to 1975, EIC has cultivated nearly 50 years of distinguished service in energy and…” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 23 | 311 contacts → | ||||
Indirect evidence “Depuis 40 ans, MANERGY s’affirme comme une société indépendante de référence, spécialisée dans l’ingénierie et le conseil en transition énergétique et environnementale.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 24 | 298 contacts → | ||||
Partial evidence “Effy, spécialiste de l’efficience énergétique.” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
| 25 | 292 contacts → | ||||
Indirect evidence “Engagé depuis 2008, Hellio est le pionnier du marché des économies d’énergie en France (métropole et Outre-Mer).” Source: RevenueBase Database · checked Sep 2, 2026Thanks. The Data Team will review it. | |||||
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 efficiency 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 efficiency consulting firms.
- Partial evidence
- Its own public description names part of energy efficiency 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 efficiency 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 11,412 energy efficiency consulting firms worldwide
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Energy efficiency consulting firms worldwide at a glance
As of Sep 2, 2026Companies by employee count
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 efficiency 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.
- Coverage
- 35 countries, largest first: the United States, France, Spain, Germany, the United Kingdom, Italy, Brazil, the Netherlands, Canada, Australia and 25 more. Country and city lists for energy efficiency consulting firms are linked below.
- What qualifies
- Companies worldwide whose own description of what they do matches “energy efficiency 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 efficiency 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 efficiency consulting firms, 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, 43,986 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 between September 2, 2026 and September 14, 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 efficiency consulting firms by location
64 lists · largest firstEvery Energy efficiency consulting firms list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.
Countries
- Energy efficiency consulting firms based in the United States2,339
- Energy efficiency consulting firms based in France1,218
- Energy efficiency consulting firms based in Spain924
- Energy efficiency consulting firms based in Germany901
- Energy efficiency consulting firms based in the United Kingdom864
- Energy efficiency consulting firms based in Italy859
- Energy efficiency consulting firms based in Brazil488
- Energy efficiency consulting firms based in the Netherlands428
- Energy efficiency consulting firms based in Canada411
- Energy efficiency consulting firms based in Australia319
- Energy efficiency consulting firms based in India304
- Energy efficiency consulting firms based in Switzerland237
- Energy efficiency consulting firms based in Belgium206
- Energy efficiency consulting firms based in Mexico178
- Energy efficiency consulting firms based in Sweden174
- Energy efficiency consulting firms based in Poland154
- Energy efficiency consulting firms based in Türkiye153
- Energy efficiency consulting firms based in Portugal151
- Energy efficiency consulting firms based in South Africa111
- Energy efficiency consulting firms based in Chile110
- Energy efficiency consulting firms based in Colombia103
- Energy efficiency consulting firms based in Ireland97
- Energy efficiency consulting firms based in Denmark82
- Energy efficiency consulting firms based in Argentina75
- Energy efficiency consulting firms based in the United Arab Emirates73
- Energy efficiency consulting firms based in Austria69
- Energy efficiency consulting firms based in Czechia57
- Energy efficiency consulting firms based in Greece56
- Energy efficiency consulting firms based in Morocco50
- Energy efficiency consulting firms based in Norway50
- Energy efficiency consulting firms based in Finland44
- Energy efficiency consulting firms based in Hungary44
- Energy efficiency consulting firms based in Saudi Arabia32
- Energy efficiency consulting firms based in Israel26
- Energy efficiency consulting firms based in New Zealand25
Cities
- Energy efficiency consulting firms based in Paris, France170
- Energy efficiency consulting firms based in Madrid, Spain168
- Energy efficiency consulting firms based in London, United Kingdom131
- Energy efficiency consulting firms based in Barcelona, Spain93
- Energy efficiency consulting firms based in New York, United States93
- Energy efficiency consulting firms based in Sao Paulo, Brazil81
- Energy efficiency consulting firms based in Houston, United States73
- Energy efficiency consulting firms based in Berlin, Germany67
- Energy efficiency consulting firms based in Toronto, Canada58
- Energy efficiency consulting firms based in Lyon, France57
- Energy efficiency consulting firms based in Sydney, Australia44
- Energy efficiency consulting firms based in Atlanta, United States38
- Energy efficiency consulting firms based in Austin, United States37
- Energy efficiency consulting firms based in Rio De Janeiro, Brazil37
- Energy efficiency consulting firms based in Roma, Italy37
- Energy efficiency consulting firms based in Chicago, United States36
- Energy efficiency consulting firms based in Hamburg, Germany35
- Energy efficiency consulting firms based in Melbourne, Australia34
- Energy efficiency consulting firms based in Dallas, United States33
- Energy efficiency consulting firms based in Milano, Italy32
- Energy efficiency consulting firms based in Denver, United States31
- Energy efficiency consulting firms based in Calgary, Canada30
- Energy efficiency consulting firms based in Portland, United States30
- Energy efficiency consulting firms based in Manchester, United Kingdom27
- Energy efficiency consulting firms based in Sevilla, Spain27
- Energy efficiency consulting firms based in Toulouse, France27
- Energy efficiency consulting firms based in Stockholm, Sweden26
- Energy efficiency consulting firms based in Vancouver, Canada25
- Energy efficiency consulting firms based in Warszawa, Poland25
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 efficiency 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 efficiency consulting firms are there worldwide?
RevenueBase identified 11,412 energy efficiency consulting firms 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?
British GAS, headquartered in Staines, tops this list with the largest team on record.
Which country has the most energy efficiency consulting firms?
The United States leads with 2,339 companies, followed by France (1,218) and Spain (924). Every energy efficiency consulting firms list by country and city is linked on this page.
Which city has the most energy efficiency consulting firms?
Madrid leads with 172 headquartered companies, followed by Paris (171) and London (135).
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 43,986 verified decision-maker contacts tracked across these 11,412 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled from the company graph between September 2, 2026 and September 14, 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.