The National Energy System Operator (NESO) has released its provisional auction results for the one-year ahead capacity auction (T-1).
The T-1 capacity auction for delivery in 2025/2026 concluded on 5 March 2025 at 10am, resulting in 7,936.289MW to be procured across 246 Capacity Market Units (CMUs). The clearing price was set at £20.00/kW/year.
In total, 725.813MW of battery energy storage system (BESS) capacity was awarded in the auction, across 78 CMUs, making up 9.15% of total awarded capacity. Furthermore, eight units with a total of 127.856MW of capacity excited the market.
Econergy’s Swangate BESS was awarded 12.543MW of capacity in the auction, while Engie secured capacity for the Broxburn and Cathkin energy storage projects for 12.896MW and 12.826MW, respectively.
Several projects owned by Gresham House Energy Storage were featured in the auction, including the Tynemouth BESS, Bloxwich BESS, Grendon project and Nevendon BESS, for a total of 28.03MW.
RWE Renewables UK secured capacity across two units for a total of 10.144MW, while Statera’s Thurrock storage project secured a total of 80.72MW across three CMUs. Zeonbe was also one of the largest winners in the auction, securing 54.300MW of capacity for the Blackhillock BESS and a total of 81.225MW of capacity for the Kilmarnock South project across six CMUs.
Of the awarded CMUs in the BESS sector, 1.5MW was awarded to BESS assets with a 0.5-hour duration, 7.116MW was awarded to 1.5-hour assets, 38.752MW was awarded to 1-hour duration assets, 6.794MW was awarded to 2.5-hour assets, and 103.833MW was awarded to 2-hour duration assets.
A total of 26.083MW of solar capacity was awarded, across 19 CMUs, making up a total of 0.33% of awarded capacity. Conrad secured 2.2MW of capacity for the Larport solar project, while EDF Energy Renewables secured 5.4MW of capacity for the Beechgreen Energy Farm and 2.680MW for the Porth Wen Solar Project.
Meanwhile, NextEnergy Solar secured 2.8MW of capacity across three CMUs and Nextpower UK secured 4.4MW of capacity across four CMUs.
