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").

02 September 2026

Gresham House Energy Storage Fund plc

(GRID or the Company)

Trading update for half-year results to 30 June 2026

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 interim results for the period ended 30 June 2026. All figures present are unaudited.

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

"The first half of 2026 marked the transition of our Growth Plan from preparation to execution. In the space of six months the Company acquired or conditionally acquired over 1GW of new capacity, fully funded the first three projects totalling 397MW and progressed those projects to construction. The Manager also made excellent progress with the augmentations of the existing portfolio and successfully completed a trial of the Alternative Revenue strategy, which significantly exceeded expectations and is moving to initial commercial-scale capacity by the end of this year.

"Behind all these actions lies one overarching objective: to maintain a meticulous focus on delivering value for shareholders by growing earnings, return on equity, and NAV per share. Reflecting that half-year progress is a 15.8% NAV increase to 131.30p per share, reinforced by higher revenues and double-digit EBITDA growth."

Highlights

-    NAV per share rose to 131.30p as of 30 June 2026 (31 Dec 2025: 113.34p), up 15.8%. The biggest driver was the revaluation of the 397MW of projects now under construction on a discounted cash flow (DCF) basis, having previously been held at cost, which contributed 14.33p of the 17.96p increase in NAV per share.

-    GRID's portfolio revenues[1] generated £34.7mn and EBITDA of £23.5mn in H1 2026, up 9.5% and 14.5% respectively from H1 2025, despite certain assets being offline some of the time for scheduled augmentation works.

-     The first three pipeline projects, Cockenzie, Monets Garden and Elland 2, totalling 397MW, reached financial close in May 2026, having raised senior project finance and export credit agency-backed facilities. Construction is now under way with target energisation in H2 2027 for Monets Garden and Elland 2 and H1 2028 for Cockenzie.

-   An additional 777MW of new projects were conditionally acquired in May 2026 and, as such, the 1,174MW of total new projects will more than double the operational capacity of the Company's portfolio.

-     Completion of a strategic JV with Summit Transition Partners (STP), itself a JV between Sumitomo Corporation and TPK Holdings. STP has taken 25% stakes in Cockenzie, Monets Garden and Elland 2, has a conditional exclusivity to take a 25% stake in Lister Drive and Ocker Hill and has a right of first offer over a 25% stake in the 480MW Rayleigh project.

-     Completion of augmentations at Glassenbury and Stairfoot adding 150MWh of operational capacity.

-     The Alternative Revenues trial, launched in December 2025, has significantly exceeded expectations. The Company has since finalised a contract with a route-to-market provider in order to scale up capacity to at least 20MW by the end of 2026.

-     On 26 June 2026, Ofgem provisionally included Ocker Hill in its list of projects set to receive 25-year cap and floor contracts under the UK Government's LDES scheme, for a 145MW / 1,160MWh eight-hour configuration. The award would bring long-term, Government-backed, index-linked revenues into the portfolio. Final awards are expected in Autumn 2026.

Unaudited NAV per share

NAV per share increased by 17.96p (+15.8%) during the period to 131.30p, up from 113.34p as of 31 December 2025.

As mentioned above, this increase was largely driven by the revaluation of the 397MW of projects now under construction, illustrating the value being created by growing the portfolio. The remaining 777MW pipeline projects conditionally acquired in the period will be held at cost until they enter construction, expected mid to late 2027, representing further potential upside to NAV.

Unlike the operational portfolio, the projects currently under construction raised debt at the SPV level. As such, the Company has updated its valuation methodology such that the discount rate applied to levered cashflows will be one percentage point higher than on unlevered projects. This was set in consultation with external advisers.

The movements in the NAV over the half year period were:

-     +14.33p from the revaluation of the new projects on a DCF basis, discussed above

-     +2.34p from cash generated by the portfolio, net of fund and operational portfolio debt costs.  

-    +0.64p from rolling the model forward and including updates to construction costs on augmentations. The roll forward is positive as the discount unwinds on augmentation projects becoming longer durations and as revenue forecasts show revenues increasing with time.

-    +0.64p from the movement in the operational debt interest rate swap as interest rates increased over the period. 

-   +0.12p from changes in revenue forecasts. This includes updates to third-party merchant revenue forecasts and minor changes to the modelling of floor contracts. In Q2 2026, the Manager applied a short-term haircut to revenue forecasts over 2026-2030[2] to reflect the current weaker trading results compared with third party curves.

-    -0.12p due to minor changes to portfolio operational cost assumptions, primarily due to increases in DNO capacity charges. The industry has raised the issue that these charges are being applied inconsistently. The Manager is working with industry groups to better understand and reduce network costs.  

Interim Results 2026

GRID expects to announce its half-year results for the period ended 30 June 2026, on 23 September. Further details, including a webinar for investors on the results, will be published closer to the time.

Portfolio performance

Both revenues and EBITDA of the GRID attributable portfolio[3] increased compared to H1 2025, up 9.5% and 14.5% to £34.7mn and £23.5mn respectively. Included in these figures is £1.1mn in liquidated damages from revenues earned through the late commissioning of the West Bradford project and £242k of net revenues from Alternative Revenues operating on a small segment of the portfolio (resulting in £205k of EBITDA contribution).

Revenue growth was primarily driven by the increase in operational MW capacity, with revenue generated per operational MW[4] decreasing to £63,200 / MW versus £75,100 / MW in H1 2025, due to a weaker merchant revenue environment and unavailability of certain assets while augmentation and maintenance works are completed.

Excluding the impact of liquidated damages, the share of merchant revenues from trading as a proportion of uncontracted revenues has continued to rise to 69% of uncontracted revenues (27% of total revenues), as expected, as frequency response continues to commoditise, falling to c.31% of uncontracted revenues (12% of total revenues).

The proportion of revenues from contracted revenues increased to 61% (H1 2025: 35%), continuing to de-risk the portfolio's revenue profile. Contracted revenues were predominantly from tolling, accounting for nearly a third of all revenue. Tolling will see its share decline as the portfolio begins to move onto floor contracts. Meanwhile, Capacity Market revenues increased as a share of total revenues from 11% to 17% as the operational portfolio has seen new contracts starting over the last year.

Growth Plan progress

At our Capital Markets Webinar in May 2026, the Manager presented a revised set of targets for the Company's Growth Plan. New projects can source capital more efficiently than augmentations and, as a result, the Growth Plan is now more ambitious, having scaled up with the addition of the Rayleigh project (480MW), offsetting a reduction in planned augmentations on the existing portfolio. The Growth Plan set out a slightly lower EBITDA annualised run rate of £141mn (previously £150mn) once the new projects and the Alternative Revenue strategy are fully operational. However, the amount of equity capital required from the Company to achieve this has reduced sharply from c.£300mn to c.£25mn, significantly improving prospective equity returns.

During the period, the first three pipeline projects secured £141mn of senior project finance, covering c.70% of project costs. We also secured export credit agency-backed facilities, the first of their kind in the UK BESS market, to fund half the BESS cost for Cockenzie and Monet's Garden.

The Company also formed a new strategic partnership with Summit Transition Partners (STP) who acquired 25% stakes in Cockenzie, Monets Garden and Elland 2 in June 2026. STP acquired its stakes at a premium to the development rights cost as the Company had de-risked the investments. STP's capital was injected following Financial Close, validating the increasing worth of these assets as they approach construction and then operations. The JV with STP creates a platform with a long-term strategic partner with whom GRID can continue to pursue its growth agenda, while not excluding other funding options.

With the increased focus on new pipeline, the Growth Plan saw augmentations reduce from the 1.5GWh originally identified to the 350MWh being delivered across eight assets in 2026 to take the portfolio's average duration to c.2.0 hours. Beyond this, the pause on further augmentation removes c.£180mn of capital expenditure, reducing the need to raise additional equity.

The Alternative Revenues strategy has moved from concept to the start of delivery and its target under the Growth Plan is unchanged: £25mn in incremental annual EBITDA when fully operational. The revenues are incremental to existing revenues and are naturally inversely correlated with the existing trading strategy, performing best in flat, low-volatility markets where the existing strategy earns least. We have extensively validated the strategy through back-testing across many years of volatile market conditions and through live revenue trials, which delivered £23 per MWh after fees, ahead of the £5-10 per MWh we expect at scale.

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

"The first half of 2026 has been a period of intense focus progressing on milestones in our Growth Plan. Our priorities for the second half of the year are clearly defined, and each translates directly into earnings and NAV per share growth. In addition, the team continues to extract value from the existing portfolio, focusing on uptime, costs and additional revenues from the traditional revenue stack. 

"We also continue to highlight to NESO the importance of it delivering on its promises to improve BESS utilisation. There is no excuse for complacency.  

"With the first three projects fully funded and in construction, we are now focused on the design, procurement, and funding on the next set of projects. These projects, especially if built as longer duration projects, will rival the largest projects built anywhere in the world for scale. Specifically, for Ocker Hill, we look forward to Ofgem's provisional cap and floor award becoming a firm contract award.

"Work is ongoing to continue to scale Alternative Revenues and we look forward to reporting on this further as it starts to move the needle on total revenues. The objective of maximising shareholder returns, and returns of equity, remains our mantra and we remain confident that we will deliver on our objectives set out in 2024, as updated in May 2026."

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
Henry Taylor

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.