UK battery storage projects won a combined 1.8GW of capacity market (CM) obligations across the T-1 and T-4 auctions.
The UK’s National Energy System Operator (NESO) released the results of its one-year ahead (T-1) and four years’ ahead (T-4) CM auctions recently.
The CM pays operators for being available during specific stress periods, forecasted based on NESO modelling on when there might be capacity shortfalls in the electricity system.
T-1 auction: BESS wins 576MW
The T-1 auction is for delivery year 2026/2027 and saw 80% of its capacity obligations filled by gas and nuclear.
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Battery energy storage system (BESS) projects won 576MW of obligations, 8.02% of the total capacity awarded.
Wind and solar also won small quantities of obligations, although as non-dispatchable technologies their role in the CM has always been very small.
The clearing price was £5/kW/year (US$6.63\kW/year), down by three quarters on last year’s.Â
The CM applies a ‘de-rating’ factor to each technology which, based on reliability, limits what portion of nameplate capacity can be bid in. It is generally highest for gas and nuclear, lower for storage, and lowest for solar and wind.
The mix of technologies is a similar to last year’s, when BESS won slightly more, 725MW, making up around 9% of the total.
Notable owner-operators with BESS projects that won in the T-1 auction include Amp Clean Energy, EDF, Engie, Greencoat, Gresham House, Harmony Energy, Low Carbon, Pulse Clean Energy, RWE, Statera as well as numerous others.
T-4 auction: 1,224MW of BESS, 1,352MW of pumped hydro
The T-4 auction for delivery in 2029/30 concluded last week (10 March) and procured 40,108.608MW of obligations, above its target of 39,400MW.
BESS projects won 1,224MW of obligations, 3.05% of the total capacity, while pumped hydro storage won 1,352MW, 3.337% of the total.
The clearing price was £27.10/kW/year, more than a 50% decrease on last year’s £60/kW/year.
Gas projects won 58.5% of the capacity awarded and interconnectors won 19.5%.
Notable owner-operators that won contracts for their battery storage projects in the T-4 included Grenergy, Gresham House, Amp Clean Energy, Eku Energy, European Energy, Harmony Energy, and many more. The CM is generally used to cover a small part of a battery project’s revenue stack.
These are extracts of articles that originally appeared on Solar Power Portal: see the full coverage of the T-1 auction here and coverage of the T-4 auction here.
