Company lists · Data refreshed September 2026

Top 25 Energy efficiency companies based in the United Kingdom

Name: Energy efficiency companies based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 15, 2026 893 companies tracked

RevenueBase identified 893 energy efficiency companies headquartered in the United Kingdom as of September 2026 and tracks 20,764 professional contacts across them, including 6,948 with verified work emails. London is the largest hub.

This list covers energy efficiency companies headquartered in the United Kingdom, 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 15, 2026.

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 15, 2026 86% judged on-target in blind review

893Companies

20,764Contacts tracked

6,948Verified emails

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The 25 largest energy efficiency companies based in the United Kingdom

Ranked by team size

Top 25 of 893 energy efficiency companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 15, 2026. RevenueBase Smart Search rates how each company's information relates to energy efficiency companies: 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	British GAS	Indirect evidence	Windsor, United KingdomHQ checked Sep 15, 2026	10001+	9,238 contacts →
	Indirect evidence “Taking care of things.” Source: RevenueBase Database · checked Sep 15, 2026
2	Shell Energy	Strong evidence	London, United KingdomHQ checked Sep 15, 2026	1,001-5,000	2,627 contacts →
	Strong evidence “We help businesses manage energy needs, boost efficiency, control costs and achieve decarbonisation goals for a better energy future.” Source: RevenueBase Database · checked Sep 15, 2026
3	EIC Partnership	Partial evidence	Redditch, United KingdomHQ checked Sep 15, 2026	51-200	316 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 15, 2026
4	E.On Control Solutions LTD	Partial evidence	Bury, United KingdomHQ checked Sep 15, 2026	201-500	206 contacts →
	Partial evidence “Who we are » The UK’s leading Energy Management company » Our aim is to increase energy performance within buildings » Deliver energy projects to maximise customer return on…” Source: RevenueBase Database · checked Sep 15, 2026
5	CFP Energy	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	201-500	171 contacts →
	Partial evidence “CFP Energy is a leading provider of energy and environmental solutions for industrial and commercial clients.” Source: RevenueBase Database · checked Sep 15, 2026
6	Consultiv Utilities	Partial evidence	Hebburn, United KingdomHQ checked Sep 15, 2026	201-500	159 contacts →
	Partial evidence “At Consultiv Utilities, we help organisations to take control of their energy strategy and support them in navigating the complexities of energy, with confidence.” Source: RevenueBase Database · checked Sep 15, 2026
7	Zenergi	Indirect evidence	Chilworth, United KingdomHQ checked Sep 15, 2026	51-200	157 contacts →
	Indirect evidence “Zenergi supports and empowers your journey to net zero.” Source: RevenueBase Database · checked Sep 15, 2026
8	Optimised	Partial evidence	Bristol, United KingdomHQ checked Sep 15, 2026	51-200	142 contacts →
	Partial evidence “Optimised exists to accelerate the shift to a low-carbon future by making energy management work; commercially, operationally and sustainably.” Source: RevenueBase Database · checked Sep 15, 2026
9	Mitie Energy	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	51-200	125 contacts →
	Partial evidence “Mitie Energy are an award-winning, UK-based energy, utilities and sustainability solutions business.” Source: RevenueBase Database · checked Sep 15, 2026
10	AMBER	Partial evidence	Cardiff, United KingdomHQ checked Sep 15, 2026	51-200	124 contacts →
	Partial evidence “We are an award-winning energy consultancy and certified B Corp™.” Source: RevenueBase Database · checked Sep 15, 2026
11	Tritility	Partial evidence	Jarrow, United KingdomHQ checked Sep 15, 2026	51-200	122 contacts →
	Partial evidence “Tritility is a UK business energy consultancy helping organisations reduce energy and overhead costs through smarter electricity, gas and water procurement.” Source: RevenueBase Database · checked Sep 15, 2026
12	Fairheat	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	51-200	115 contacts →
	Partial evidence “If you are operating a heat network, or planning a new heat network, then FairHeat can ensure that you get maximum efficiency from your heat networks while reducing operating and…” Source: RevenueBase Database · checked Sep 15, 2026
13	ZTP	Indirect evidence	London, United KingdomHQ checked Sep 15, 2026	51-200	115 contacts →
	Indirect evidence “At ZTP, we’re committed to accelerating the transition to a more sustainable future by reducing the negative impact of human activity on our planet - ecologically, financially…” Source: RevenueBase Database · checked Sep 15, 2026
14	Longevity Partners	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	51-200	115 contacts →
	Partial evidence “Longevity Partners is a multidisciplinary energy and sustainability consultancy.” Source: RevenueBase Database · checked Sep 15, 2026
15	TROO	Partial evidence	Doxford International Business Park, United KingdomHQ checked Sep 15, 2026	51-200	106 contacts →
	Partial evidence “Managing business energy can be overwhelming.” Source: RevenueBase Database · checked Sep 15, 2026
16	best.energy	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	51-200	97 contacts →
	Partial evidence “Best.Energy is a UK based company specialising in the measurement, control and reduction of energy consumption and costs within the industrial, commercial and public sectors.” Source: RevenueBase Database · checked Sep 15, 2026
17	Haven Power	Indirect evidence	Ipswich, United KingdomHQ checked Sep 15, 2026	201-500	97 contacts →
	Indirect evidence “Haven Power is rebranding as Drax and we’ll soon be retiring this account.” Source: RevenueBase Database · checked Sep 15, 2026
18	Laser Energy	Partial evidence	West Malling, United KingdomHQ checked Sep 15, 2026	51-200	93 contacts →
	Partial evidence “At LASER Energy, part of the Commercial Services Group Energy & Environment portfolio, a wholly-owned business unit of Kent County Council, we help public sector organisations…” Source: RevenueBase Database · checked Sep 15, 2026
19	The Green Energy Advice Bureau	Partial evidence	Sunderland, United KingdomHQ checked Sep 15, 2026	51-200	90 contacts →
	Partial evidence “The Green Energy Advice Bureau are a leading independent award-winning UK commercial energy consultancy.” Source: RevenueBase Database · checked Sep 15, 2026
20	Alfa Energy An Edison Energy Company	Partial evidence	London, United KingdomHQ checked Sep 15, 2026	201-500	88 contacts →
	Partial evidence “Alfa Energy Group (an Edison Energy company) is an international energy, sustainability and technology consultant partner with 200 employees over four international locations.” Source: RevenueBase Database · checked Sep 15, 2026
21	Team Energy Auditing Agency LTD	Strong evidence	Milton Keynes, United KingdomHQ checked Sep 15, 2026	51-200	69 contacts →
	Strong evidence “TEAM is the UK’s leading supplier of carbon and energy management solutions committed to driving the efficiency and sustainability of energy consumption and environmental…” Source: RevenueBase Database · checked Sep 15, 2026
22	Direct Business Solutions	Partial evidence	Houghton Le Spring, United KingdomHQ checked Sep 15, 2026	51-200	67 contacts →
	Partial evidence “As one of the largest energy consultancies in the UK, Direct Business Solutions can take the hassle out of business utilities with comprehensive utility management services.” Source: RevenueBase Database · checked Sep 15, 2026
23	ECO Logic Partners	Partial evidence	Team Valley, United KingdomHQ checked Sep 15, 2026	11-50	66 contacts →
	Partial evidence “We bring good energy to the table to help you save yours.” Source: RevenueBase Database · checked Sep 15, 2026
24	Birdsall Group LTD	Strong evidence	Hemel Hempstead, United KingdomHQ checked Sep 15, 2026	51-200	64 contacts →
	Strong evidence “Our History Birdsall are an innovative company with a 48-year track record of delivering energy efficiency and environmental solutions to our clients.” Source: RevenueBase Database · checked Sep 15, 2026
25	Cenergist	Strong evidence	Washington, United KingdomHQ checked Sep 15, 2026	201-500	62 contacts →
	Strong evidence “Cenergist is a specialist energy and water efficiency company in the UK and Europe.” Source: RevenueBase Database · checked Sep 15, 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: energy efficiency companies. 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 companies.
Partial evidence: Its own public description names part of energy efficiency companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name energy efficiency companies. 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 893 energy efficiency companies based in the United Kingdom

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Energy efficiency companies based in the United Kingdom at a glance

As of Sep 15, 2026

33.5%Verified-email coverage

23.3Average contacts per company

1-10Median size (employees)

13.3%Largest-city concentration · London

Sep 15, 2026Page data refreshed

Companies by employee count

1-10

492

11-50

298

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 893 companies.

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 companies, 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.
What qualifies: Companies headquartered in the United Kingdom whose own description of what they do matches “energy efficiency companies”. 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 companies), 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 companies, and records with no verified work email. Companies headquartered outside United Kingdom 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 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, 6,948 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 15, 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 companies by metro

Energy efficiency companies in London119
Energy efficiency companies in Manchester27

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 companies, 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 companies are there based in the United Kingdom?

RevenueBase identified 893 energy efficiency companies headquartered in the United Kingdom 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 Windsor, tops this list with the largest team on record.

Which city has the most energy efficiency companies?

London leads with 119 headquartered companies, followed by Manchester (27) and Leeds (14).

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 6,948 verified decision-maker contacts tracked across these 893 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 15, 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.