June-end 2026 Quarterly NAV and Portfolio Update

15 September 2026

Gore Street Energy Storage Fund plc

(the 'Company' or 'GSF')

June-end 2026 Quarterly NAV and Portfolio Update

NAV stable outside of dividend payments, updated strategy enabling distributions and capital recycling

The GSF Board today announces the Company's unaudited Net Asset Value ('NAV') as at 30 June 2026 ('Q1 FY26/27' or 'the Quarter'), together with an update on the portfolio and progress on execution of the refreshed strategy.

Q1 FY26/27 Highlights

·    Unaudited NAV was 71.94 pence per share (31 March 2026: 74.90 pence per share); +0.29 pence per share excluding the 3.25 pence per share of dividends paid in the Quarter.

·    Overall quarterly revenue increased by c.38% year-on-year to £9.77 million (Q1 FY25/26: £7.07 million), driven by the portfolio's increased operational capacity. Revenue per MW per hour reduced to £6.95/MW/hr (Q1 FY25/26: £8.07/MW/hr) shaped by several market-specific conditions, clearly set out below.

·    Continued execution of the strategy announced in March 2026:

o  the Company's first two asset sales were completed in August 2026;

o  ordinary dividends of 1.75 pence per share have been declared in respect of each applicable quarter post-strategy update (Dec-end 2025, March-end 2026, and June-end 2026), in line with the commitment to distribute 7.0 pence per share annually; and

o  the Stony and Ferrymuir assets augmentations from one-hour to two-hour durations remain on schedule for completion by end of December 2026.

·    As at 30 June 2026, the Group (the Company and its subsidiaries) remained well-capitalised and funded with £35.0 million of cash or cash equivalents, drawn debt of £114.6 million, equal to c.24% of Gross Asset Value ('GAV'), and £28.9 million of undrawn debt capacity remaining, comfortably below the Company's 30% GAV ratio limit (Q4 FY25/26: cash of £51.6 million, drawn debt of £105.8 million, and £37.8 million of undrawn debt capacity).

o  The figures are presented as at 30 June 2026, before the receipt of cash from the sales of Mucklagh and Kilmannock and prior to dividends paid after the period.

Quarterly Unaudited Net Asset Value ('NAV') Movements

Unaudited NAV as at 30 June 2026 decreased by 2.96 pence to 71.94 pence per share (31 March 2026: 74.90 pence per share). Key macro valuation assumptions: revenue curves, inflation, and discount rates, remained unchanged from the valuation as at 31 March 2026 as these assumptions are updated at the half-year and full-year periods. The Directors have evaluated the need for disclosures and/or adjustments resulting from post balance sheet events. As a result, the valuation was adjusted to reflect the transaction valuations of the Mucklagh and Kilmannock assets.

·    Rollover (+£10.08m/+2.00p): reflecting the effect of the passage of time as forecast cash flows for the Quarter are assumed received and future cash flows are now closer to the present, so their discounted value has increased.

·  Actuals (-£3.49m/-0.69p): reflecting the variance between the portfolio's realised performance and forecasts assumed in the prior valuation. Further details on revenue performance over the Quarter are outlined below.

·    Operating Expenditure (-£2.49m/-0.49p): the Company's operating expenses, including project oversight costs, routine operations and maintenance (O&M), and other associated costs to run the assets.

·    Dividends (-£16.42m/-3.25p): the 1.5 pence per share special dividend and 1.75 pence per share regular dividend paid during the Quarter and declared in respect of the December-end 2026 quarter.

·    Other Valuation Movements (-£2.63m/-0.52p): updated capex forecasts, revised project timelines, and foreign exchange (FX) movements over the period. Included within this line is the positive impact of the post-period sale value. Much of the downward movement reflects a revised grid connection cost estimate for the Middleton asset. This follows an updated offer from National Grid Electricity Transmission (NGET) correcting a previously understated charge; the asset's grid connection date, capacity and milestones remain unchanged.

·    The transaction consideration from the completed sales of the Irish projects, Mucklagh and Kilmannock contributed +0.36 pence per share to NAV compared to the March 2026 valuation.

Q1 FY26/27 Revenue Updates

Year-on-year, total revenue increased, driven largely by the Big Rock asset (California, 200 MW) becoming operational in mid-2025. However, average revenue per MW per hour for the portfolio decreased vs the same period of the prior year, reflecting conditions such as oversaturation of BESS in GB and milder weather conditions reducing volatility in Texas.

GB revenue fell by c.33% year-on-year (Q1 FY25/26: £6.52/MW/hr), as a 10% year-on-year rise in day-ahead spreads was more than offset by a decrease in some of the ancillary services prices in an increasingly saturated market.

Ireland revenue increased by c.8% YoY (Q1 FY25/26: £13.79/MW/hr). Despite the previously reported reduction in the pricing rate applied to the variable DS3 uncapped contract, the assets operating under the DS3 uncapped contract (Mulavilly and Drumkee) spent materially more time earning the scheme's higher scalar rates, driven by continued renewable build out, increased wind generation and the Green link interconnector. The fixed-rate contract (DS3 Capped) was unchanged.

In Germany, revenue was c.15% lower than the same period in the previous year (Q1 FY25/26: £20.28/MW/hr), though remained a very lucrative market for the Company, generating the highest average revenue of the five markets the Company is active in, and almost 4x higher than average GB revenue over the period. The market continues to be characterised by strong demand for grid balancing services (aFRR), given the large build out of renewables on the grid, in particular with high levels of  solar power in the spring and summer further increasing the need to balance the grid.

Texas revenue rose by c.6% year-on-year in absolute terms, though on a per MW/hr basis, it saw revenue c.36% lower (Q1 FY25/26: £2.68/MW/hr) as installed BESS capacity increased. Milder weather and more renewable output also contributed to narrower spreads and ancillary prices. A new market design (RTC+B) has made Ancillary Services procurement more efficient, applying downward pressure to prices.

In California, the Company's 200 MW asset contributed c.£3.7m in the quarter; there is no comparable prior year period as the asset was not operational in Q1 FY25/26. This was supported by a fixed contract (Resource Adequacy), and higher availability incentive payments. A new market known as the Extended Day-Ahead Market that opened in May, supported a 40% quarter-on quarter uplift in ancillary services revenue.

Progress Being Achieved on the Company's Strategy

In March 2026, the Board announced its updated strategy, and significant progress has been made:

1.    Enhanced Shareholder Distributions: the Company has declared three quarterly dividends of 1.75 pence per share since the update, in line with its 7.0 pence per share annual target. On 1 September, the Board declared its dividend for the June-end 2026 quarter, to be paid on or around 9 October 2026.

2.  Disposals and JVs: Post-period, in August, the Company completed its first two disposals under the updated strategy - the Mucklagh (75 MW) and Kilmannock (120 MW) pre-construction assets in the Republic of Ireland - sold at levels not below the previous combined NAV of £13.6 million, making significant progress toward the Company's FY26/27 KPI of £25 million in disposal proceeds.

a.    Sales processes are ongoing at Cremzow (22 MW, Germany) and Middleton (200 MW, GB).

b.    In addition to the assets already announced for sale, the Company continues to evaluate additional assets for disposal, and options for a wider JV at a HoldCo level or a group sale of assets.

3.   Capital Recycling: Two-hour assets have been shown to increase value and revenue potential over one-hour assets in markets such as GB. Accordingly, the Company has set out milestones around capital recycling through development and augmentation. The Stony (79.9 MW) and Ferrymuir (49.9 MW) augmentation projects remain on schedule and in line with the Manager's expectations and will add c.130 MWh of capacity. The sites are expected to begin operation as two-hour systems by end of December 2026.

Other Portfolio Updates

·    Enderby: The Enderby (57 MW, GB) project, is completing the final stages of full compliance testing with the grid operator. As referenced in the Annual Report, Enderby is earning some revenue, but is not yet able to access all revenue streams, and therefore its full revenue potential. The Company is exploring contractual delay provisions, as it has successfully done previously for delayed projects. Accordingly, the GB Q1 revenue outlined in the table above does not reflect the full operational revenues expected in future periods from this asset.

Angus Gordon Lennox, Chair of the Company, said: "The refreshed Board is encouraged by the stability in NAV over the Quarter and the operational progress made on the updated strategy set out in March: two asset disposals have been completed, reinvestments into augmentation works are on track to deliver a significant 130MWh of additional capacity, and distributions to all Shareholders are continuing in line with the commitment made."

- Ends -

For further information:  

Gore Street Investment Management Limited

Alex O'Cinneide / Ben Paulden                                              Tel: +44 (0) 20 4551 1382

Email: [email protected]                                    

Shore Capital (Joint Corporate Broker) 

Anita Ghanekar / Sophie Collins (Corporate Advisory)                            Tel: +44 (0) 20 7408 4090

Fiona Conroy (Corporate Broking)

J.P. Morgan Cazenove (Joint Corporate Broker)               

William Simmonds / Rupert Budge                                                             Tel: +44 (0) 20 3493 8000

Burson Buchanan (Media Enquiries)      

Henry Wilson / Henry Harrison-Topham / Nick Croysdill                        Tel: +44 (0) 20 7466 5000

Email: [email protected]    

https://www.gsenergystoragefund.com