Company lists · Data refreshed October 2026

Top 25 Energy efficiency nonprofits based in the United Kingdom

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

Compiled by the RevenueBase Data Team Data refreshed Oct 12, 2026 333 companies tracked

RevenueBase identified 333 company matches for energy efficiency nonprofits associated with the United Kingdom as of October 2026 and tracks 3,612 professional contacts across them, including 1,250 with verified work emails. London is the largest hub.

This list covers company matches for energy efficiency nonprofits associated with the United Kingdom, 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.

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

333Companies

3,612Contacts tracked

1,250Verified emails

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The 25 largest energy efficiency nonprofits based in the United Kingdom

Ranked by team size

Top 25 of 333 company matches for energy efficiency nonprofits based in the United Kingdom, 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	STARK	Exact match	Horley, United KingdomHQ recorded Oct 12, 2026	201-500	453 contacts →
	Exact match “Our mission: We’ve been on a mission to help identify energy waste, save costs and reduce carbon emissions for more than 40 years.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
2	Energy Saving Trust	Exact match	London, United KingdomHQ recorded Oct 12, 2026	201-500	440 contacts →
	Exact match “Energy Saving Trust is an independent organisation dedicated to promoting energy efficiency, low carbon transport and sustainable energy use.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
3	Centre For Sustainable Energy	Exact match	Bristol, United KingdomHQ recorded Oct 12, 2026	51-200	113 contacts →
	Exact match “We are a national charity that shares our knowledge and experience to help people change the way they think and act on energy.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
4	Agilityeco	Exact match	Sutton, United KingdomHQ recorded Oct 12, 2026	51-200	86 contacts →
	Exact match “At AgilityEco our vision is a warm, healthy home for everyone.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
5	Pacific Green	Exact match	London, United KingdomHQ recorded Oct 12, 2026	51-200	58 contacts →
	Exact match “Pacific Green is becoming a world leader at providing sustainable cleantech solutions to help solve climate warming, green energy and resource scarcity challenges.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
6	GEO Green Energy Options	Exact match	Hardwick, United KingdomHQ recorded Oct 12, 2026	51-200	57 contacts →
	Exact match “Since 2006, we’ve been on a mission to make home energy tech that’s easy to use and understand, reduces energy costs, increases comfort and looks great in people’s homes.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
7	IZ Energy Services LTD	Exact match	Barking, United KingdomHQ recorded Oct 12, 2026	51-200	54 contacts →
	Exact match “IZ Energy is pioneering a sustainable future.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
8	Tomato Energy	Exact match	Basingstoke, United KingdomHQ recorded Oct 12, 2026	51-200	47 contacts →
	Exact match “We are Tomato Energy, and our mission is to empower UK communities to live sustainably, maximising green energy and keeping costs low.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
9	Cotswold Energy Group	Exact match	Stonehouse, United KingdomHQ recorded Oct 12, 2026	51-200	47 contacts →
	Exact match “Secure your greener future with renewable energy solutions!” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
10	The Improveasy Group	Exact match	Altrincham, United KingdomHQ recorded Oct 12, 2026	51-200	46 contacts →
	Exact match “Energy solutions made easy.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
11	Severn WYE	Exact match	Gloucester, United KingdomHQ recorded Oct 12, 2026	51-200	46 contacts →
	Exact match “Severn Wye changes the way people, businesses and communities use energy, to meet the urgent need for warm, healthy homes now, and to create a low-carbon future driven by clean…” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
12	Electron Green	Exact match	London, United KingdomHQ recorded Oct 12, 2026	11-50	46 contacts →
	Exact match “Electron Green provides a unique and simple route to low-cost solar electricity for businesses across Europe.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
13	Green Home Systems	Exact match	Irvine, United KingdomHQ recorded Oct 12, 2026	51-200	42 contacts →
	Exact match “At Green Home Systems, we deliver whole-house retrofit solutions that make homes warmer, more energy efficient, and lower cost to run.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
14	Effective Home	Exact match	Doncaster, United KingdomHQ recorded Oct 12, 2026	51-200	41 contacts →
	Exact match “Effective Home was established in 2016 to help homeowners make their homes more energy efficient, save money and reduce their carbon footprint.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
15	Savemoneycutcarbon	Exact match	Bury St Edmunds, United KingdomHQ recorded Oct 12, 2026	11-50	41 contacts →
	Exact match “SaveMoneyCutCarbon helps organisations reduce energy, water and carbon consumption across their buildings and operations.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
16	Carbon Rewind	Exact match	Watford, United KingdomHQ recorded Oct 12, 2026	51-200	39 contacts →
	Exact match “At Carbon Rewind, we are optimistic about the energy future of the UK, and committed to doing our part to deliver the vision of a more sustainable future.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
17	On-Site Energy LTD	Exact match	Liverpool, United KingdomHQ recorded Oct 12, 2026	11-50	33 contacts →
	Exact match “On-Site Energy was founded to support energy intensive manufacturers to improve their energy efficiency and achieve their sustainability goals through innovation and an…” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
18	Olympus Power LTD	Exact match	Exeter, United KingdomHQ recorded Oct 12, 2026	11-50	32 contacts →
	Exact match “Olympus Power is an award-winning Energy Concierge, helping UK businesses take greater control of their energy strategy, costs and long-term resilience.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
19	Scis Group	Exact match	Fareham, United KingdomHQ recorded Oct 12, 2026	51-200	31 contacts →
	Exact match “Hello.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
20	Eden Sustainable LTD	Exact match	City Of London, United KingdomHQ recorded Oct 12, 2026	11-50	30 contacts →
	Exact match “Eden Sustainable helps UK organisations cut energy costs, reduce carbon and future-proof their operations through intelligently designed commercial solar and energy infrastructure.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
21	Infinity Energy Organisation	Exact match	London, United KingdomHQ recorded Oct 12, 2026	51-200	29 contacts →
	Exact match “At Infinity, our mission is to help home owners reduce their energy bills and carbon footprint.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
22	Heat Geek	Exact match	London, United KingdomHQ recorded Oct 12, 2026	11-50	28 contacts →
	Exact match “Heat Geek is renewing the heating industry.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
23	The MCS Foundation	Exact match	Cheshire, United KingdomHQ recorded Oct 12, 2026	1-10	27 contacts →
	Exact match “Our vision is to make every UK home carbon-free.” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
24	Plymouth Energy Community	Exact match	Plymouth, United KingdomHQ recorded Oct 12, 2026	11-50	27 contacts →
	Exact match “Plymouth Energy Community (PEC) is an independent charity established in June 2013 to empower our community to create a fair, affordable, zero carbon energy system with local…” Recorded in the RevenueBase company graph · Oct 12, 2026 · View company records in RevenueBase
25	DOMNA	Exact match	London, United KingdomHQ recorded Oct 12, 2026	51-200	24 contacts →
	Exact match “At Domna, we are on a mission to make every home in Great Britain green and sustainable.” 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 nonprofits”. 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 333 energy efficiency nonprofits based in the United Kingdom

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Energy efficiency nonprofits based in the United Kingdom at a glance

As of Oct 12, 2026

34.6%Verified-email coverage

10.8Average contacts per company

1-10Median size (employees)

15.9%Largest-city concentration · London

Oct 12, 2026Page data refreshed

Companies by employee count

1-10

179

11-50

110

51-200

201-500

1,001-5,000

5,001-10,000

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 333 companies.

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.
What qualifies: Company records associated with the United Kingdom whose business descriptions match “energy efficiency nonprofits” 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. Where headquarters information is recorded, preview rows are also filtered to this page’s location. 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 1,250 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 nonprofits by metro

Energy efficiency nonprofits in London53

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 nonprofits”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many energy efficiency nonprofits are there based in the United Kingdom?

RevenueBase identified 333 company matches for energy efficiency nonprofits associated with the United Kingdom 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?

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

Which city has the most energy efficiency nonprofits?

London leads with 53 company records, followed by Manchester (14) and Liverpool (7).

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 1,250 professional contacts with verified work emails tracked across these 333 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.