Company lists · Data refreshed September 2026

Top 25 Green hydrogen investment firms based in London, United Kingdom

Name: Green hydrogen investment firms based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 28, 2026 55 companies tracked

RevenueBase identified 55 green hydrogen investment firms headquartered in London, United Kingdom as of September 2026 and tracks 466 professional contacts across them, including 219 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers green hydrogen investment firms headquartered in London, 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 28, 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 28, 2026 86% judged on-target in blind review

55Companies

466Contacts tracked

219Verified emails

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The 25 largest green hydrogen investment firms based in London, United Kingdom

Ranked by team size

Top 25 of 55 green hydrogen investment firms based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to green hydrogen investment firms: 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	Climate Investment CI	Partial evidence	London, United KingdomHQ checked Sep 28, 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 28, 2026
2	National Energy	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	51-200	41 contacts →
	Indirect evidence “Founded in 2018 by ambitious entrepreneurs, National Energy is a US-backed, privately funded group active globally across the renewable energy sector.” Source: RevenueBase Database · checked Sep 28, 2026
3	Supercritical	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	39 contacts →
	Strong evidence “The world's first high pressure, ultra-efficient electrolyser for the lowest cost of pressurised green hydrogen.” Source: RevenueBase Database · checked Sep 28, 2026
4	AP Ventures	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	31 contacts →
	Indirect evidence “AP Ventures is an independent venture capital firm headquartered in London, with offices in San Francisco and South Africa.” Source: RevenueBase Database · checked Sep 28, 2026
5	Clean Energy Transition LLP	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	14 contacts →
	Partial evidence “Clean Energy Transition LLP is an investment management partnership focused on fundamental equity investing.” Source: RevenueBase Database · checked Sep 28, 2026
6	Oort Energy	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	14 contacts →
	Strong evidence “Oort Energy is a manufacturer of green hydrogen systems for energy storage and clean fuel.” Source: RevenueBase Database · checked Sep 28, 2026
7	Clean Growth Fund	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	13 contacts →
	Indirect evidence “CGF invest in tech innovations that reduce greenhouse gas emissions or improve resource efficiency across power, transport, industry, buildings, waste and water.” Source: RevenueBase Database · checked Sep 28, 2026
8	Buckthorn Partners LLP	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	11 contacts →
	Indirect evidence “Buckthorn invests in industrial businesses providing products and services that support the growth and integration of renewable energy, lower emissions, energy efficiency and…” Source: RevenueBase Database · checked Sep 28, 2026
9	Susten	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	11 contacts →
	Indirect evidence “We invest in new energy technologies.” Source: RevenueBase Database · checked Sep 28, 2026
10	Telis Energy	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	11 contacts →
	Partial evidence “Telis Energy is a UK-based green energy projects developer and investor.” Source: RevenueBase Database · checked Sep 28, 2026
11	Cerulean Winds	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	9 contacts →
	Indirect evidence “Our aim is to lead on scaled floating wind.” Source: RevenueBase Database · checked Sep 28, 2026
12	First Imagine	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	9 contacts →
	Indirect evidence “Early-stage venture capital investor focused on technologies driving the Energy transition.” Source: RevenueBase Database · checked Sep 28, 2026
13	Sabien Technology Group PLC	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	8 contacts →
	Indirect evidence “Sabien Technology Group is a company focused on building a portfolio of solutions, in the heating, cooling and transportation sectors, that deliver immediate reductions in CO2…” Source: RevenueBase Database · checked Sep 28, 2026
14	Delta H	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	8 contacts →
	Indirect evidence “Delta H is a consultancy dedicated to accelerating the transition to zero carbon energy systems.” Source: RevenueBase Database · checked Sep 28, 2026
15	Conduit Ventures Limited	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	8 contacts →
	Partial evidence “Impact-driven venture and growth capital fund centred on Energy Decarbonization, Hydrogen, Water risks/Food Security and AI driven solutions.” Source: RevenueBase Database · checked Sep 28, 2026
16	Earlsfield Energy	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	5 contacts →
	Indirect evidence “Earlsfield Energy is an energy infrastructure platform focused on delivering scalable, high-performance power solutions for the rapidly expanding AI and data centre industry.” Source: RevenueBase Database · checked Sep 28, 2026
17	Meld Energy	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	5 contacts →
	Strong evidence “Meld Energy is a large scale UK green hydrogen developer with ambitions to produce 10%+ of country's electrolytic hydrogen powered by renewable energy.” Source: RevenueBase Database · checked Sep 28, 2026
18	Fuse Energy	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	5 contacts →
	Indirect evidence “We are building a full stack renewable energy company to accelerate global renewable energy transition.” Source: RevenueBase Database · checked Sep 28, 2026
19	Shorelight Partners	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	4 contacts →
	Indirect evidence “Shorelight supports the Energy Transition towards lower emissions by investing in assets and technologies that operate in the lower carbon energy value chain, or help high…” Source: RevenueBase Database · checked Sep 28, 2026
20	Gluon Renewable Energies	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	3 contacts →
	Strong evidence “Investment holding company and strategic investment into sustainability focused companies and projects including e-mobility, the hydrogen economy and deeptech” Source: RevenueBase Database · checked Sep 28, 2026
21	Renergia Holdings LTD	Indirect evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	3 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 28, 2026
22	Aurium Capital	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	2 contacts →
	Partial evidence “Founded in 2011, Aurium is an award-winning, mid-market investment firm dedicated to delivering a fairer, more sustainable planet.” Source: RevenueBase Database · checked Sep 28, 2026
23	HYVIZ	Strong evidence	London, United KingdomHQ checked Sep 28, 2026	11-50	1 contacts →
	Strong evidence “HyViz Ltd is a leading low-cost Green Hydrogen and Green Ammonia producer.” Source: RevenueBase Database · checked Sep 28, 2026
24	Nano Vida Tech	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	1 contacts →
	Partial evidence “Investment holding company for the worlds most innovative solutions to enable climate change mitigation and investment decisions to coexist.” Source: RevenueBase Database · checked Sep 28, 2026
25	Dolphyn Hydrogen	Partial evidence	London, United KingdomHQ checked Sep 28, 2026	1-10	1 contacts →
	Partial evidence “At Dolphyn Hydrogen, we share a common belief that hydrogen is a critical component of our low carbon energy future and supporting enhancement of energy security whilst supporting…” Source: RevenueBase Database · checked Sep 28, 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: green hydrogen investment 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 green hydrogen investment firms.
Partial evidence: Its own public description names part of green hydrogen investment firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name green hydrogen investment 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 55 green hydrogen investment firms based in London, United Kingdom

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Green hydrogen investment firms based in London, United Kingdom at a glance

As of Sep 28, 2026

47.0%Verified-email coverage

8.5Average contacts per company

1-10Median size (employees)

Sep 28, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 55 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 green hydrogen investment 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.
What qualifies: Companies headquartered in London, United Kingdom whose own description of what they do matches “green hydrogen investment 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 green hydrogen investment 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 green hydrogen investment firms, and records with no verified work email. Companies headquartered outside London 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, 219 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 28, 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.

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 green hydrogen investment 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 green hydrogen investment firms are there based in London, United Kingdom?

RevenueBase identified 55 green hydrogen investment firms headquartered in London, 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?

Climate Investment CI, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most green hydrogen investment firms?

London leads the United Kingdom with 55 headquartered companies, followed by Edinburgh (5) and Bristol (3).

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 219 verified decision-maker contacts tracked across these 55 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 28, 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.