HydrogenOne Capital Growth plc ("HydrogenOne" or the "Company")

LEI: 213800PMTT98U879SF45

NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN OR INTO THE UNITED STATES, AUSTRALIA, CANADA, JAPAN OR THE REPUBLIC OF SOUTH AFRICA OR ANY OTHER JURISDICTION IN WHICH THE RELEASE, PUBLICATION OR DISTRIBUTION OF THIS ANNOUNCEMENT WOULD BE UNLAWFUL.

This announcement is an advertisement and does not constitute a prospectus and investors must subscribe for any shares referred to in this announcement only on the basis of information contained in the summary, registration document and securities note published by the Company on 26 September 2022 ("Prospectus") as supplemented by the Supplementary Prospectus (as defined below) and not in reliance on this announcement. This announcement is for information purposes only and does not constitute an offer for sale or subscription of any securities in the Company.

4 April 2023

Publication of Supplementary Prospectus

HydrogenOne has today published a supplementary prospectus approved by the Financial Conduct Authority. The publication of the supplementary prospectus is a regulatory requirement under the Prospectus Regulation Rules following the publication of the Company's audited financial report and financial statements for the period ended 31 December 2022.

The supplementary prospectus is supplemental to, and should be read in conjunction with, the Prospectus and circular published by the Company on 26 September 2022 in relation to the issue of new shares pursuant to the Company's share issuance programme.

A copy of the supplementary prospectus will shortly be available on the Company's website (www.hydrogenonecapitalgrowthplc.com), at the Company's registered office at 6th Floor, 125 London Wall, London, EC2Y 5AS, and at the National Storage Mechanism via  https://data.fca.org.uk/#/nsm/nationalstoragemechanism.

For further information, please contact:

About HydrogenOne:

HydrogenOne is the first London-listed hydrogen fund investing in clean hydrogen for a positive environmental impact. The Company was launched in 2021 with an investment objective to deliver an attractive level of capital growth by investing in a diversified portfolio of hydrogen and complementary hydrogen focussed assets. INEOS Energy is a strategic investor in HydrogenOne. The Company is listed on the London Stock Exchange's main market (ticker code: HGEN). The Company is an Article 9 climate impact fund with an ESG policy integrated in investment decisions and asset monitoring.

The Company's Investment Adviser, HydrogenOne Capital LLP (FRN: 954060), is an appointed representative of Thornbridge Investment Management LLP (FRN: 713859) which is authorised and regulated by the Financial Conduct Authority.

IMPORTANT NOTICE

Neither this announcement, nor any copy of it, may be taken or transmitted, published or distributed, directly or indirectly, in or into the United States or any other jurisdiction where to do so would constitute a violation of the relevant securities laws of such jurisdiction. This Announcement is for information purposes only and does not constitute an offer to sell or issue, or the solicitation of an offer to buy, acquire or subscribe for any shares in the Company.

The Ordinary Shares have not been, and will not be, registered under the US Securities Act of 1933, as amended (the "US Securities Act"), or under any securities laws of any state or other jurisdiction of the United States and may not be offered, sold, resold, transferred or delivered, directly or indirectly, in or into the United States except pursuant to an applicable exemption from, or in a transaction not subject to, the registration requirements of the US Securities Act and in compliance with the securities laws of any state or other jurisdiction of the United States.

This announcement has been issued by, and is the sole responsibility of, the Company. No undertaking, representation, warranty or other assurance, express or implied, is made or given by or on behalf of the Company or any member of the Company's group, HydrogenOne Capital LLP, Barclays Bank PLC ("Barclays") or any of their respective directors, officers, partners, employees, agents or advisers or any other person as to the accuracy or completeness of the information or opinions contained in this announcement and no responsibility or liability is accepted by any of them for any such information or opinions or for any errors, omissions or misstatements, negligence or otherwise in this announcement.

Barclays, which is authorised by the Prudential Regulation Authority and regulated in the United Kingdom by the Financial Conduct Authority and the Prudential Regulation Authority, is acting exclusively for the Company and no one else in connection with the matters referred to in this announcement and will not be responsible to anyone other than the Company for providing advice in relation to the matters referred to in this announcement.