Company lists · Data refreshed September 2026

Top 25 Climate tech startups based in the United Kingdom

Name: Climate tech startups based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 347 companies tracked

RevenueBase identified 347 climate tech startups headquartered in the United Kingdom as of September 2026 and tracks 26,133 professional contacts across them, including 10,566 with verified work emails. London is the largest hub.

This list covers climate tech startups 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 19, 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 19, 2026 86% judged on-target in blind review

347Companies

26,133Contacts tracked

10,566Verified emails

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The 25 largest climate tech startups based in the United Kingdom

Ranked by team size

Top 25 of 347 climate tech startups based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to climate tech startups: 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	Subsea7	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	10001+	12,645 contacts →
	Indirect evidence “Subsea7 makes offshore energy transition possible through the continuous evolution of lower-carbon oil and gas and by enabling the growth of renewables and emerging energy.” Source: RevenueBase Database · checked Sep 19, 2026
2	Anthesis Group	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	1,001-5,000	894 contacts →
	Indirect evidence “Anthesis guides clients to sustainable performance.” Source: RevenueBase Database · checked Sep 19, 2026
3	KBC A Yokogawa Company	Indirect evidence	Walton-on-thames, United KingdomHQ checked Sep 19, 2026	201-500	658 contacts →
	Indirect evidence “We are passionate about driving sustainable change for our planet.” Source: RevenueBase Database · checked Sep 19, 2026
4	Energy Saving Trust	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	201-500	426 contacts →
	Indirect evidence “Energy Saving Trust is an independent organisation dedicated to promoting energy efficiency, low carbon transport and sustainable energy use.” Source: RevenueBase Database · checked Sep 19, 2026
5	Avantis	Indirect evidence	Cardiff, United KingdomHQ checked Sep 19, 2026	501-1,000	213 contacts →
	Indirect evidence “Avantis Group, based in the UK, is a global leader in energy and transportation.” Source: RevenueBase Database · checked Sep 19, 2026
6	Carbon Clean	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	188 contacts →
	Indirect evidence “Carbon Clean is the point-source carbon capture expert, driving the decarbonisation of hard-to-abate industries for more than 15 years.” Source: RevenueBase Database · checked Sep 19, 2026
7	CFP Energy	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	201-500	171 contacts →
	Indirect evidence “CFP Energy is a leading provider of energy and environmental solutions for industrial and commercial clients.” Source: RevenueBase Database · checked Sep 19, 2026
8	AMP Clean Energy	Indirect evidence	Holborn, United KingdomHQ checked Sep 19, 2026	51-200	134 contacts →
	Indirect evidence “We are AMP We are an energy company that turns sustainability ambitions into reality.” Source: RevenueBase Database · checked Sep 19, 2026
9	First Mode	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	201-500	93 contacts →
	Indirect evidence “First Mode develops and manufactures decarbonization solutions for heavy industry partners dedicated to the clean energy future.” Source: RevenueBase Database · checked Sep 19, 2026
10	Storegga	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	83 contacts →
	Indirect evidence “Storegga, a business established in 2020 as an independent champion for the development of carbon reduction and carbon removal technologies.” Source: RevenueBase Database · checked Sep 19, 2026
11	clearvue.business	Indirect evidence	Gateshead, United KingdomHQ checked Sep 19, 2026	51-200	81 contacts →
	Indirect evidence “We enable businesses to succeed in the environmental components of their ESG strategies through comprehensive net zero consulting services and ground-breaking carbon and energy…” Source: RevenueBase Database · checked Sep 19, 2026
12	Ashden	Partial evidence	London, United KingdomHQ checked Sep 19, 2026	11-50	76 contacts →
	Partial evidence “Ashden's mission is to accelerate transformative climate solutions and build a more just world.” Source: RevenueBase Database · checked Sep 19, 2026
13	Team Energy Auditing Agency LTD	Indirect evidence	Milton Keynes, United KingdomHQ checked Sep 19, 2026	51-200	69 contacts →
	Indirect 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 19, 2026
14	City Science	Indirect evidence	Exeter, United KingdomHQ checked Sep 19, 2026	51-200	68 contacts →
	Indirect evidence “CARBON FIRST ENGINEERING City Science is the first engineering company dedicated to decarbonisation.” Source: RevenueBase Database · checked Sep 19, 2026
15	Pacific Green	Partial evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	63 contacts →
	Partial evidence “Pacific Green is becoming a world leader at providing sustainable cleantech solutions to help solve climate warming, green energy and resource scarcity challenges.” Source: RevenueBase Database · checked Sep 19, 2026
16	Climate Connect Digital	Strong evidence	London, United KingdomHQ checked Sep 19, 2026	11-50	63 contacts →
	Strong evidence “Climate Connect Digital (CCD) is a climate-tech company with Digital Monitoring Reporting Verification products in carbon markets.” Source: RevenueBase Database · checked Sep 19, 2026
17	Climate Investment CI	Partial evidence	London, United KingdomHQ checked Sep 19, 2026	51-200	62 contacts →
	Partial evidence “Climate Investment is a US and UK-based independently managed specialist investor focused on accelerating capital-efficient decarbonization of heavy emitting sectors.” Source: RevenueBase Database · checked Sep 19, 2026
18	Catagen Limited	Indirect evidence	Belfast, United KingdomHQ checked Sep 19, 2026	51-200	50 contacts →
	Indirect evidence “CATAGEN’s mission is to clean and decarbonise the air.” Source: RevenueBase Database · checked Sep 19, 2026
19	Progressive Energy	Indirect evidence	Stonehouse, United KingdomHQ checked Sep 19, 2026	11-50	42 contacts →
	Indirect evidence “Taking carbon out of the world by developing low carbon energy projects.” Source: RevenueBase Database · checked Sep 19, 2026
20	Syzygy	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	11-50	35 contacts →
	Indirect evidence “Founded in 2010, Syzygy is the leading specialist low carbon technology consultancy for the real estate sector.” Source: RevenueBase Database · checked Sep 19, 2026
21	Angara Global LTD UK	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	11-50	33 contacts →
	Indirect evidence “ANGARA turns $100 billion of invisible fouling losses into measurable profit through Proactive Fouling Management in industrial heat transfer with paired AI analytics and patented…” Source: RevenueBase Database · checked Sep 19, 2026
22	Elire Group	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	11-50	32 contacts →
	Indirect evidence “ELIRE pioneers innovative solutions that enable our clients and partners to reach their decarbonisation and net zero goals.” Source: RevenueBase Database · checked Sep 19, 2026
23	Zestec Renewable Energy	Indirect evidence	Bournemouth, United KingdomHQ checked Sep 19, 2026	11-50	28 contacts →
	Indirect evidence “Owned by funds advised by Octopus Energy Generation, one of Europe’s largest renewable energy investors currently managing renewable assets totalling more than £5bn, we are…” Source: RevenueBase Database · checked Sep 19, 2026
24	Caldera	Indirect evidence	Fareham, United KingdomHQ checked Sep 19, 2026	11-50	26 contacts →
	Indirect evidence “Caldera is here to make zero-carbon heat the norm.” Source: RevenueBase Database · checked Sep 19, 2026
25	Carbon Limiting Technologies	Indirect evidence	London, United KingdomHQ checked Sep 19, 2026	11-50	24 contacts →
	Indirect evidence “At CLT, we believe clean technology is essential to building a resilient, competitive, and sustainable economy.” Source: RevenueBase Database · checked Sep 19, 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: climate tech startups. 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 climate tech startups.
Partial evidence: Its own public description names part of climate tech startups, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name climate tech startups. 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 347 climate tech startups based in the United Kingdom

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Climate tech startups based in the United Kingdom at a glance

As of Sep 19, 2026

40.4%Verified-email coverage

75.3Average contacts per company

1-10Median size (employees)

49.0%Largest-city concentration · London

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

228

11-50

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 347 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 climate tech startups, 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 “climate tech startups”. 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 climate tech startups), 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 climate tech startups, 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, 10,566 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 19, 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.

Climate tech startups by metro

Climate tech startups in London170

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 climate tech startups, 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 climate tech startups are there based in the United Kingdom?

RevenueBase identified 347 climate tech startups 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?

Subsea7, headquartered in London, tops this list with the largest team on record.

Which city has the most climate tech startups?

London leads with 170 headquartered companies, followed by Manchester (12) and Edinburgh (10).

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 10,566 verified decision-maker contacts tracked across these 347 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 19, 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.