Company lists · Data refreshed October 2026

Top 25 Energy efficiency consulting services worldwide

Name: Energy efficiency consulting services worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Oct 12, 2026 17,818 companies tracked

RevenueBase identified 17,818 company matches for energy efficiency consulting services worldwide as of October 2026 and tracks 189,804 professional contacts across them, including 59,274 with verified work emails. The United States is the largest market and London the largest hub.

This list covers company matches for energy efficiency consulting services worldwide, 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 October 12, 2026. Country and city lists for energy efficiency consulting services follow the table.

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 Oct 12, 2026 How this list was built

17,818Companies

189,804Contacts tracked

59,274Verified emails

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The 25 largest energy efficiency consulting services worldwide

Ranked by team size

Top 25 of 17,818 company matches for energy efficiency consulting services worldwide, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Oct 12, 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.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	British GAS	Exact match	Windsor, United KingdomHQ recorded Oct 12, 2026	10001+	9,535 contacts →
	Exact match “Taking care of things.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
2	ERM	Exact match	London, United KingdomHQ recorded Oct 12, 2026	5,001-10,000	9,532 contacts →
	Exact match “Sustainability is our business.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
3	Dalkia	Exact match	Saint-andré-lez-lille, FranceHQ recorded Oct 12, 2026	10001+	8,823 contacts →
	Exact match “Dalkia : ensemble, relevons le défi climatique!” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
4	Enova By Veolia	Exact match	Dubai, United Arab EmiratesHQ recorded Oct 12, 2026	5,001-10,000	4,030 contacts →
	Exact match “Enova is the regional leader in integrated energy and multi-technical services, delivering comprehensive services to its clients.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
5	Mckinstry	Exact match	Seattle, WA, United StatesHQ recorded Oct 12, 2026	1,001-5,000	2,293 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 · Oct 12, 2026 · View company records in RevenueBase
6	Clearesult	Exact match	Austin, TX, United StatesHQ recorded Oct 12, 2026	1,001-5,000	2,206 contacts →
	Exact match “CLEAResult is the largest provider of energy efficiency, energy transition and energy sustainability services in North America.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
7	Ameresco	Exact match	Framingham, MA, United StatesHQ recorded Oct 12, 2026	1,001-5,000	1,513 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 · Oct 12, 2026 · View company records in RevenueBase
8	OLA	Exact match	Austin, TX, United StatesHQ recorded Oct 12, 2026	n/a	1,150 contacts →
	Exact match “OLA Sustainability, LLC OLA Sustainability is a consulting firm that focuses on integrating sustainable practices into commercial and multifamily design projects.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
9	GK	Exact match	Oslo, NorwayHQ recorded Oct 12, 2026	1,001-5,000	1,134 contacts →
	Exact match “GK er en ledende teknisk entreprenør og servicepartner.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
10	Willdan	Exact match	Anaheim, CA, United StatesHQ recorded Oct 12, 2026	1,001-5,000	872 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 · Oct 12, 2026 · View company records in RevenueBase
11	Syska Hennessy Group	Exact match	New York, United StatesHQ recorded Oct 12, 2026	501-1,000	835 contacts →
	Exact match “Consult Engineer Commission At Syska Hennessy Group, we create exceptional environments.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
12	Resource Innovations	Exact match	Half Moon Bay, CA, United StatesHQ recorded Oct 12, 2026	501-1,000	774 contacts →
	Exact match “Resource Innovations (RI) is an energy transformation firm.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
13	Inerco	Exact match	Seville, SpainHQ recorded Oct 12, 2026	1,001-5,000	735 contacts →
	Exact match “INERCO is a multinational technology company specialising in sustainability.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
14	3e Engenharia EM Eficiencia Energetica	Exact match	BrazilHQ recorded Oct 12, 2026	201-500	530 contacts →
	Exact match “A 3E Engenharia atua nacionalmente, oferecendo soluções para empresas concessionárias de serviços públicos, no planejamento, gestão, execução e inovação em projetos de Eficiência…” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
15	Korra Energi	Exact match	Cairo, EgyptHQ recorded Oct 12, 2026	1,001-5,000	476 contacts →
	Exact match “Korra Energi is a proud Egyptian leader in energy efficiency and construction services, backed by over 25 years of expertise and a vision of "Growth and Prosperity"(إعمار الأرض).” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
16	Tecno Group	Exact match	Naples, ItalyHQ recorded Oct 12, 2026	201-500	430 contacts →
	Exact match “We are an Energy Digital and Sustainable Company specialized in sustainability consulting services and 4.0 solutions.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
17	Veolia Industries Global Solutions	Exact match	Aubervilliers, FranceHQ recorded Oct 12, 2026	1,001-5,000	429 contacts →
	Exact match “Veolia Industries Global Solutions est devenu Veolia Energie Performance depuis le 1er juin 2025.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
18	TRIO	Exact match	Irvine, CA, United StatesHQ recorded Oct 12, 2026	201-500	387 contacts →
	Exact match “We are Trio – global energy and sustainability advisors.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
19	P2s	Exact match	Long Beach, CA, United StatesHQ recorded Oct 12, 2026	201-500	381 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 · Oct 12, 2026 · View company records in RevenueBase
20	Budderfly	Exact match	Shelton, CT, United StatesHQ recorded Oct 12, 2026	201-500	380 contacts →
	Exact match “Budderfly is redefining how energy efficiency, resilience, and grid participation can work together across America’s commercial sector.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
21	AESA	Exact match	Barcelona, SpainHQ recorded Oct 12, 2026	n/a	376 contacts →
	Exact match “Ingeniería y Consultoría Energética orientada a la búsqueda y el desarrollo de soluciones energéticas de alta eficiencia para sus Clientes.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
22	MCW Group Of Companies	Exact match	Toronto, ON, CanadaHQ recorded Oct 12, 2026	201-500	370 contacts →
	Exact match “Since 1964 the MCW Group has built a solid reputation for the delivery of Professional Consulting Engineering Services, Energy Management Services, and Engineering Development…” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
23	Greenflex	Exact match	Paris, FranceHQ recorded Oct 12, 2026	501-1,000	368 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
24	Wendel Companies	Exact match	Williamsville, NY, United StatesHQ recorded Oct 12, 2026	201-500	367 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 · Oct 12, 2026 · View company records in RevenueBase
25	NUS Consulting Group	Exact match	Park Ridge, NJ, United StatesHQ recorded Oct 12, 2026	201-500	360 contacts →
	Exact match “National Utility Service, Inc.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “energy efficiency consulting services”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 17,818 energy efficiency consulting services worldwide

See the full list, filter by size, metro and specialty, and access 59,274 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Energy efficiency consulting services worldwide at a glance

As of Oct 12, 2026

31.2%Verified-email coverage

10.7Average contacts per company

1-10Median size (employees)

1.1%Largest-city concentration · London

Oct 12, 2026Page data refreshed

Companies by employee count

1-10

11,677

11-50

4,782

51-200

985

201-500

174

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency is reported on each country list linked below.

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.
Coverage: Every country. Country and city lists for energy efficiency consulting services are linked below.
What qualifies: Company records worldwide whose business descriptions match “energy efficiency consulting services” 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. 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 59,274 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 October 12, 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.

Energy efficiency consulting services by location

82 lists · largest first

Every Energy efficiency consulting services 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 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 “energy efficiency consulting services”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many energy efficiency consulting services are there worldwide?

RevenueBase identified 17,818 company matches for energy efficiency consulting services worldwide as of October 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?

British GAS tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which country has the most energy efficiency consulting services?

The United States leads with 2,516 companies, followed by France (1,335) and the United Kingdom (1,152). Every energy efficiency consulting services list by country and city is linked on this page.

Which city has the most energy efficiency consulting services?

London leads with 194 company records, followed by Paris (192) and Madrid (186).

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 59,274 professional contacts with verified work emails tracked across these 17,818 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 October 12, 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.