Unaudited NAV as of 31 Dec 2025 and Trading Update

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").

4 March 2026

Gresham House Energy Storage Fund plc

("GRID" or the "Company")

Unaudited NAV as of 31 December 2025 and Trading Update

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 provide the following trading update ahead of the publication of its annual results for the year ended 31 December 2025, expected in April 2026. All figures presented are unaudited.

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

"This year we have successfully executed on our Three-year Plan, achieving meaningful growth in terms of revenues, EBITDA, and operational capacity. Melksham, Shilton Lane and West Bradford all becoming revenue generating means that the Company has now scaled up to over 1GW to be able to generate substantial operational cashflows. The portfolio's improving quality and value is reflected in an increased NAV of 3.7% from last year, despite headwinds from third party revenue curves.

While the focus continues to be on plan delivery and its impact on NAV growth, we are also encouraged by investors' renewed confidence, as demonstrated by a narrowing discount during the past year. We look forward to communicating further progress in the annual report and throughout 2026."

Highlights

- Unaudited NAV per share of 113.34p as of 31 December 2025, up 3.7% year over year (31 Dec 2024: 109.35p) and down 2.0% in the last quarter (30 Sept 2025: 115.68p).

- Unaudited Operational Portfolio revenues in 2025 increased 29.9% to £60.4mn, (FY24: £46.5mn)

- Unaudited Operational Portfolio EBITDA increased 33.4% to £38.8mn, (FY24: £29.1mn) resulting in an EBITDA margin of 64.2% in 2025 (FY24: 62.5%)

- Melksham (100MW/200MWh), West Bradford (87MW/174MWh) and Shilton Lane (40MW/80MWh) became fully operational during the year, increasing operational capacity by 26.9% to 1,072MW (31 Dec 2024: 845MW)

- £220mn amortising debt facility closed replacing the previous facility. This debt was secured on improved terms to the previous facility.

Unaudited NAV per share

Actions by the Company, including the first year of implementation of the Three-year Plan, drove NAV growth in 2025 despite headwinds from falling third-party revenue curves. These actions included the commissioning of Melksham, West Bradford and Shilton Lane as well as embarking on eight new project augmentations financed through the larger operational debt facility.

Acquisitions of land and the negotiation of lease extensions have reduced operating costs and increased asset lives of the relevant projects. Similarly, reduced insurance costs and completion of construction projects below budget also contributed to higher valuations. Overall, this has improved project economics and cash generation, while at the same time increasing the overall quality and long-term potential of the portfolio.

Cockenzie, Monet's Garden and Elland 2, for which share purchase agreements were signed in December 2025, are held at cost. Once their project financing is completed and construction is underway, expected later in H1 2026, these projects will be valued on a discounted cash flow basis and gains on revaluation will be recognised at that time.

There was an increase in NAV per share in the year of 3.99p. This was the result of positive actions taken by the Company (13.63p) as well as cash generated by the portfolio (5.35p) and other movements totalling 0.62p. This was partially offset by the negative impact from the downward movement in revenue curves, which declined further in Q4 2025. Across the full year, revenue curves led to reduction in NAV per share of 15.61p. The long-term floor contracts on 939MW of the portfolio, which by virtue of the falling revenue curves now represent a larger percentage of forecast revenue, represents a considerable derisking of the long-term revenue expectations for the Company's assets. Meanwhile, underlying discount rates have remained unchanged, resulting in a Weighted Average Discount Rate of 10.33% at the year-end (31 Dec 2024: 10.73%).

Portfolio performance

Both revenues and underlying operational portfolio EBITDA increased meaningfully in 2025, up 29.9% and 33.4% respectively.

Revenue growth was primarily driven by stronger revenue generation from existing operational capacity with the portfolio generating £68.6k/MW/year, up from £59.8k/MW/year in FY2024. In addition, the three newly commissioned projects served to increase grid connection and energy storage capacity (227MW and 454MWh respectively), thereby increasing revenue, although they only became fully operational towards the end of the year and so the full year impact from these projects has yet to come through.

This has improved the EBITDA margin of the portfolio from 62.5% to 64.2% due to the higher revenues generated on a largely fixed cost base. This is also despite some capacity going offline as projects go through augmentation.

There is still room for improvement in the revenue environment. The National Energy System Operator's ("NESO") continued improvements to the Balancing Mechanism should result in a fairer market where BESS assets can earn consistently higher revenues than they do today.

Three-year Plan progress

In August 2025, the Company closed a £220mn, seven?year, amortising debt facility, replacing existing borrowing of £160mn, providing c. £60mn in capital for the execution of the Three-year Plan. This debt was secured on improved terms to the previous facility. A portion of the £60m is being used to fund the new wave of augmentations, with eight projects being upgraded during 2026 adding 300MWh to operational capacity.

The Glassenbury (50MW) augmentation has been funded through a third-party equity injection at the project level and is expected to be revenue generating in the coming weeks. The Stairfoot (40MW) augmentation is also expected to be re-energised in the coming weeks. Meanwhile, the Red Scar (50MW) and Roundponds (20MW) augmentations are under construction and are expected to be energised by the end of Q2 2026. The remaining four augmentation projects (Tynemouth, Rufford, York and Thurcroft) will go into construction in Q2 2026 and are set to be completed in Q4 2026.

The construction of the new pipeline projects is also progressing. Agreements for the acquisition of the first three projects (397MW) were signed in December 2025. Financing for these projects is almost complete, with the major remaining hurdle to closing and commencement of full construction works being the receipt of "Gate 2" grid connection offers following the Queue Reform process.

In a positive development, Cockenzie, the largest of the three projects at 240MW, has received its Gate 2 offer. Early works have begun on all three projects, and long lead items have been ordered to preserve the construction programmes' timings and deliver the Three-year Plan.

In addition, the Company expects to sign agreements for the remaining two projects identified under the Three-year Plan, Lister Drive and Ocker Hill, in the near future, with construction now likely to start in early 2027 as Queue Reform delays result in later connection dates. While this is a delay to the original timings, it provides the Manager the opportunity to seek new lower cost designs, potentially at a longer duration.

The Company is also working to potentially add further projects beyond the current horizon to continue our exciting growth trajectory.

The final element of the Three-year Plan - Alternative Revenues - has made meaningful progress with ongoing live trials since December 2025. More information on these trials and next steps will be provided in the upcoming Annual Report.

Update on the Queue Reform process

NESO announced on 13th February 2026 a revised timetable for projects receiving their connection offers as part of the Queue Reform process. The delayed timetable is preventing us from closing financing and beginning construction on our new pipeline. The impact is wider reaching than just GRID, with the build-out of the whole electricity industry on pause whilst this process is concluded.

Cockenzie has received its new connection offer from NESO with a connection date of June 2027. Monet's Garden, Lister Drive and Ocker Hill are transmission network projects which were all expected to receive revised connection offers in January 2026; under the updated timetable from NESO we are to receive offers between now and mid-April 2026.

Elland 2, which is a distribution network project, was previously expected to receive its connection offer between January and March 2026, and this is now expected between March and May 2026.

The Company's pipeline projects all have protected status and therefore are expected to have reasonably near-term connection dates once final offers are received. Once offers are received, we expect to close funding for the first three pipeline projects, Cockenzie, Monet's Garden and Elland 2.

Ben Guest, Fund Manager of Gresham House Energy Storage Fund plc & Managing Director of Gresham House New Energy, added:

"We are pleased with GRID's financial performance in 2025, during which cash generation improved markedly. We are close to concluding the funding of new projects and starting construction, without needing to raise equity at the Fund level.

We are working hard to deliver on the huge growth opportunity for this Company, both in terms of capacity (new pipeline and augmentations) and revenues (driven by capacity, improving revenue rates as the skip rate starts to fall and Alternative Revenues).

2026 promises to be another year of substantial execution of several Three-year Plan milestones that have been a matter of serious and dedicated commitment by the Manager's team, and the Board."

For further information, please contact:

Gresham House Energy Transition

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

Harry Hutchinson

Jefferies International Limited

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

Peel Hunt

Luke Simpson +44 (0) 20 7418 8900

Huw Jeremy

KL Communications [email protected]Charles Gorman +44 (0) 20 3882 6644Charlotte Francis

JTC (UK) Limited as Company Secretary [email protected] Ruth Wright +44 (0) 20 7409 0181

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.