Strategic Joint Venture

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION AS STIPULATED UNDER THE MARKET ABUSE REGULATION (EU NO. 596/2014) AS IT FORMS PART OF UK DOMESTIC LAW BY VIRTUE OF THE EUROPEAN UNION (WITHDRAWAL) ACT 2018 ("MAR").

27 May 2026

Gresham House Energy Storage Fund plc

(GRID or the Company)

Strategic Joint Venture with Summit Transition Partners

Gresham House Energy Storage Fund plc (LSE:GRID), the UK's largest listed fund investing in utility-scale battery energy storage systems (BESS), is pleased to announce a new long-term strategic partnership with Sumitomo Corporation and TPK Holdings.

Transaction details

GRID has entered into a strategic partnership with Summit Transition Partners (STP), a joint venture between Sumitomo Corporation, an integrated trading and investment company engaged in diverse businesses with a strong global network, and Taiwan based TPK Holdings, a leading manufacturer specializing in touchscreen technology and supply chain management.

STP will provide equity funding for certain pipeline projects, as well as providing access to significant international energy expertise. The partnership represents a further endorsement of GRID's market-leading platform, proven track record and continued growth strategy.

The signed Exclusivity Agreement governs the acquisition by STP of a 25% shareholding in each of the project holding companies of the first three projects in the pipeline; Cockenzie (240MW/480MWh), Monets Garden (57MW/114MWh) and Elland 2 (100MW/200MWh) via agreed execution form transaction documents. The majority of the consideration for these investments is paid at completion of transaction documents which is anticipated over the next week, with a smaller proportion deferred until key construction milestones are achieved. These three projects are due to start construction immediately.

STP also has exclusivity in respect to a 25% holding of Lister Drive (57MW/114MWh) and Ocker Hill (240MW/480MWh) based on similar agreed economic terms. These investments are expected to conclude at a later date after acquisition by GRID and once financing is arranged.

John Leggate CBE, Chair of Gresham House Energy Storage Fund plc, commented:

"We are delighted to sign this agreement with Summit Transition Partners and deepen the relationship with Sumitomo and TPK. The anticipated transaction demonstrates GRID's continued ability to raise capital at a project level, despite GRID trading at a discount to NAV.

Importantly, we are partnering with Sumitomo Corporation and TPK Holdings, combining global reach and deep expertise right across the energy sector and the associated supply chain ecosystem. This partnership is a strong endorsement of the quality of GRID's assets, its valuations, and its future growth prospects. This demonstrates another example of how GRID continues to raise equity funding to drive growth in a capital constrained environment.

We look forward to working closely with our partners as we continue to scale the platform and capitalise on the significant opportunities in battery energy storage."

Seiji Kitajima, Managing Executive Officer, General Manager of Energy Innovation Initiative (EII), Sumitomo Corporation, added:

"We are pleased to enter this partnership with Gresham House Energy Storage Fund and Gresham House, a leading platform in the UK battery energy storage sector. By combining GRID's proven development and operational capabilities with Sumitomo Corporation's global energy expertise and battery-related know-how developed through our operation in Japan, we aim to accelerate the deployment of energy storage solutions. Through this partnership we seek to contribute to the reliability and resilience of power systems amid the ongoing energy transition, while supporting the continued growth of GRID's platform."

Foster Chiang, Vice Chairman of TPK Holding Co., Ltd., added:

"By combining Sumitomo's global leadership in energy storage development and optimisation, as well as GRID's providing immediate access to a scaled, high-quality portfolio and pipeline in the most advanced market, together with TPK's advanced supply chain capabilities, STP is uniquely positioned to capture immediate opportunities across the rapidly expanding BESS market."

ENDS

For further information, please contact:

Gresham House Energy Transition

Ben Guest                                                                   +44 (0) 20 3837 6270
James Bustin

Harry Hutchinson

Jefferies International Limited

Gaudi Le Roux                                                            +44 (0) 20 7029 8000
Stuart Klein
Harry Randall 

Peel Hunt                                                                  

Luke Simpson                                                             +44 (0) 20 7418 8900

Huw Jeremy                          

KL Communications                                                 [email protected]

Charles Gorman                                                         +44 (0) 20 3882 6644
Charlotte Francis

JTC (UK) Limited as Company Secretary              [email protected]

Ruth Wright                                                                +44 (0) 20 7409 0181

LEI: 213800MSJXKH25C23D82

About the Company and the Manager

Gresham House Energy Storage Fund plc aims to invest in a diversified portfolio of utility-scale battery energy storage systems (known as BESS) located in Great Britain and internationally. The Company seeks to provide investors with the prospect of capital growth through the re-investment of net cash generated in excess of its target dividend in accordance with the Company's investment policy.

Gresham House Asset Management Ltd is the FCA authorised operating business of Gresham House Ltd, a specialist alternative asset manager. Gresham House is committed to operating responsibly and sustainably, taking the long view in delivering sustainable investment solutions.

www.greshamhouse.com

Definition of utility-scale battery energy storage systems (BESS)

Utility-scale battery energy storage systems (BESS) are the enabling infrastructure that will support the continued growth of renewable energy sources such as wind and solar, essential to the UK's stated target to reduce carbon emissions. They store excess energy generated by renewable energy sources and then release that stored energy back into the grid during peak hours when there is increased demand.

DISCLAIMERS

This announcement has been prepared for information purposes only. This announcement does not constitute a prospectus relating to the Company and does not constitute, or form part of, any offer or invitation to sell or issue, or any solicitation of any offer to subscribe for, any shares in the Company in any jurisdiction nor shall it, or any part of it, or the fact of its distribution, form the basis of, or be relied on in connection with or act as any inducement to enter into, any contract therefor. The merits or suitability of any securities must be independently determined by the recipient on the basis of its own investigation and evaluation of the Company. Any such determination should involve, among other things, an assessment of the legal, tax, accounting, regulatory, financial, credit and other related aspects of the securities.

This announcement may not be used in making any investment decision in isolation. This announcement on its own does not contain sufficient information to support an investment decision and investors should ensure that they obtain all available relevant information before making any investment. This announcement does not constitute or form part of and may not be construed as an offer to sell, or an invitation to purchase or otherwise acquire, investments of any description, nor as a recommendation regarding the possible offering or the provision of investment advice by any party. No information in this announcement should be construed as providing financial, investment or other professional advice and each prospective investor should consult its own legal, business, tax and other advisers in evaluating the investment opportunity. No reliance may be placed for any purposes whatsoever on this announcement or its completeness.

The information and opinions contained in this announcement are provided as at the date of the announcement and are subject to change without notice and no representation or warranty, express or implied, is or will be made in relation to the accuracy or completeness of the information contained in this announcement and no responsibility, obligation or liability or duty (whether direct or indirect, in contract, tort or otherwise) is or will be accepted by the Company, the Manager or any of their affiliates or by any of their respective officers, employees or agents to update or revise publicly any of the statements contained in this announcement. No reliance may be placed for any purpose whatsoever on the information or opinions contained in this announcement or on its completeness, accuracy or fairness. The document has not been approved by any competent regulatory or supervisory authority.

Any investment in the Company is speculative, involves a high degree of risk, and could result in the loss of all or substantially all of an investment in the Company. Results can be positively or negatively affected by market conditions beyond the control of the Company or any other person. There can be no assurance that any targeted returns will be achieved or that the Company will be able to implement its investment strategy or achieve its investment objectives. There is no guarantee that any such returns can be achieved or can be continued if achieved, nor that the Company will make any distributions whatsoever.

The information in this announcement may include forward-looking statements, which are based on the current expectations, intentions and projections about future events and trends or other matters that are not historical facts and in certain cases can be identified by the use of terms such as "may", "will", "should", "expect", "anticipate", "project", "estimate", "intend", "continue", "target", "believe" (or the negatives thereof) or other variations thereof or comparable terminology. These forward-looking statements, as well as those included in any related materials, are not guarantees of future performance and are subject to known and unknown risks, uncertainties, assumptions about the Company and other factors, including, among other things, the development of its business, trends in its operating industry, and future capital expenditures and acquisitions. In light of these risks, uncertainties and assumptions, the events in the forward-looking statements may not occur and actual results may differ materially from those expressed or implied by such forward looking statements. Given these risks and uncertainties, prospective investors are cautioned not to place undue reliance on forward-looking statements.

Each of the Company, the Manager and their affiliates and their respective officers, employees and agents expressly disclaim any and all liability which may be based on this announcement and any errors or omissions from this announcement.

No representation or warranty is given to the achievement or reasonableness of future projections, management targets, estimates, prospects or returns, if any. Any views contained in this announcement are based on financial, economic, market and other conditions prevailing as at the date of this announcement. The information contained in this announcement will not be updated.