THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF THE MARKET ABUSE REGULATION (EU 596/2014) WHICH IS PART OF UK LAW BY VIRTUE OF THE EUROPEAN UNION (WITHDRAWAL) ACT 2018.

20 November 2025

Gresham House Energy Storage Fund plc

("GRID" or the "Company")

Q3 2025 NAV announcement

Gresham House Energy Storage Fund plc (LSE: GRID), the UK's largest fund investing in utility-scale battery energy storage systems (BESS), is pleased to announce its Net Asset Value (NAV) at 30 September 2025 of £658.3mn or 115.68p per share, up 7.4% in the quarter (30 June 2025: 107.71p).

Highlights as of 30 September 2025

·    During the quarter, the most significant changes to NAV per share included:

o  +4.07p reflecting the benefit of increased cashflows from new augmentations now funded by the refinancing and the lowering of discount rate premiums for projects previously in construction as they move to "in commissioning"

o  +2.10p from improvement in third party revenue forecasts

o  +1.31p from model roll forward

o  +0.42p from operating cost revisions. Insurance costs across the portfolio have reduced which was partially offset by increases to grid charges

o  -0.25p from delays to operational start dates at West Bradford and Shilton Lane

o  +0.23p from the net of working capital generation, fund, and debt costs. This was lower than prior quarters due to the one-off cost of unwinding of arrangement fees on the refinancing of the previous debt

o  +0.06p from the inclusion of the previously announced floor contracts. As disclosed in the 2025 Interim Report, the contracted element of the floors uses a discount rate of 7.5% and a merchant upside rate of 11.35%

o  +0.04p from the movement in interest rate swaps

·    No changes to inflation assumptions or underlying discount rates were made during the period, other than the inclusion of the new floor discount rates.

·    Weighted average discount rate (WADR) is 10.46% for the full portfolio including projects under construction and 10.35% for the operational portfolio.

·    Operational assets[1] are valued at an average of £717k/MW. Discounted cashflows represented £706k/MW of the total while working capital represented the remainder.

·    Operational capacity was 1,072MW / 1,701MWh on 30 September with West Bradford and Shilton Lane energised in the period and expected to be revenue generating in December 2025.

·    In August the Company completed the refinancing of its operational debt facilities. The refinancing replaced existing facilities with a £220mn loan with a seven-year legal maturity and an amortisation profile over 14 years. The new facility attracts a margin of 225bps over SONIA compared with 300bps for the previous facility.

·    Total debt drawn at the end of the period was £210mn and cash on hand between the Company and its investments was £78.0mn. The gives a net debt to NAV ratio of 20.1%.

Portfolio Update

The underlying portfolio generated revenues of £13.3mn and EBITDA of £8.8mn in Q3 2025. The summer months tend to have lower revenues for BESS due to seasonal reductions in demand and power price spreads, as well as lower weightings on Capacity Market payments. Merchant levels are expected to increase again in Q4 as electricity demand ramps up.

Shilton Lane (40MW / 80MWh) and West Bradford (87MW / 174MWh) are in commissioning and are expected to be revenue-generating by December 2025. These two projects and Melksham (100MW / 200MWh), which became fully operational in October, all have a 50bps premium applied to their respective discount rates in the Q3 NAV as they were in commissioning at the quarter end.  It is expected that at the year-end stage all three sites will be fully operational, and that the premium can be removed, providing an uplift to NAV on these sites.

The valuations this quarter include the seven remaining augmentations (out of eight) of the operational portfolio sites which have now been funded through the refinancing process. Glassenbury, the first additional augmentation, was included in Q2 2025 NAV when the external equity funding was secured for this project. The projects are all being augmented to at least 2 hours and, altogether, will increase the capacity of the operational portfolio by 350MWh. The NAV impact of these augmentations will increase as the completion of works approaches (from the unwinding of discounting on the higher 2-hour revenue curve).

None of the new pipeline projects referred to in the interims have been included in the Q3 NAV as they had not been acquired by the quarter end. Elland 2 is the first asset of the new pipeline to be acquired, also announced today, and others are at an advanced stage. The project financing for these projects is progressing well and, once this is concluded, construction will follow shortly after and the value of these assets, on a discounted cashflow basis, will subsequently be reflected in the NAV.

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

"We are pleased to announce a meaningful uplift in NAV this quarter, driven primarily by our strategic initiatives, and we thank our shareholders for their patience and conviction in our growth strategy. The growth unlocked by the recent refinancing funds the next wave of augmentations and that work is moving at pace. Increasing the capacity of the operational portfolio is a critical pillar of our Three-Year Plan and it is welcome to see the first stage of this plan bearing tangible results."

Ben Guest, Fund Manager of Gresham House Energy Storage Fund plc & Managing Director of Gresham House Energy Transition, said:

"Completing the refinancing has laid the groundwork for the next stage of growth for the Company. As well as closely monitoring the progress of our eight augmentations, the Manager's focus is now on finalising the acquisition of the new pipeline projects and the associated financing. Once completed, we will start construction on these assets which will also bring a significant uplift in NAV as well as delivering associated earnings once becoming operational."

ENDS

For further information, please contact:

                                                                       
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.