Batteries make strong contribution in Belgium’s latest capacity market auctions
Source：pv magazine
Battery storage continues to dominate new-build capacity contracted in Belgium’s capacity market auctions. In return, the capacity remuneration mechanism (CRM) payments play a key role in supporting these projects by providing guaranteed revenues, which help leverage bank financing.
On the last day of October, Belgian transmission system operator Elia published the results of the three CRM auctions, held simultaneously for the first time this year: Y-4, Y-2, and Y-1. Elia reported that all auctions – each with its own focus and time horizon – ran smoothly and on schedule, “meaning that security of supply for the 2026–2027 delivery year is fully guaranteed,” while significant steps have been taken toward ensuring supply in subsequent years.
“The results indicate a competitive market with sufficient liquidity and a strong contribution from batteries. Moreover, the cost of ensuring security of supply will be lower for 2026–2027 than for 2025–2026,” Elia said in a statement.
Y-1 auction for the 2026-2027 delievery year
In the Y-1 auction for the 2026–2027 delivery year, 73 units – including batteries, gas plants, and demand response – offered 5,697 MW, exceeding the adjusted demand of 4,555 MW. A total of 56 units were selected, providing 4,556 MW, of which 171 MW was new capacity.
The total cost of €125.4 million (€20.2k/MW) is lower than last year’s €182.9 million (€25.7k/MW). The weighted average price of €14.1k/MW/year remains well below the intermediate price cap (IPC) of €22.7k/MW/year.
One final Y-1 auction for the 2027–2028 delivery year will be held in 2026, and Elia expects the remaining volumes to be secured. Several batteries with Y-4 contracts are likely to contribute earlier, while many projects – particularly battery and demand-side management initiatives – expressed interest but were not yet ready to proceed due to permitting or technical uncertainties.
Y-2 auction for the 2027-2028 delievery year
This year marked the first-ever Y-2 auction for the 2027–2028 delivery year, designed to provide an additional safeguard for security of supply. For the 2027–2028 delivery year, the volume was initially set at 5,370 MW and later adjusted to 3,590 MW after eligibility corrections. A total of 51 CRM units offered 3,238 MW, and since supply was below demand, all projects were contracted.
The results included 3,010 MW of existing capacity, 66 MW of refurbished capacity, and 162 MW of new capacity – notably 60 MW (123 MW nominal) of new batteries and 102 MW (225 MW nominal) of batteries already contracted in earlier auctions for an additional one-year term. The price stood at €25.1k/MW/year (below the IPC of €28.6k/MW/year).
The latest procurements brings the cumulative contracted capacity for the 2027–2028 delivery period to 6,472 MW (including both Y-4 and Y-1 auctions). Of this, 2,177 MW represents new capacity secured across all auctions – comprising 1,617 MW from CCGT plants and 560 MW (1,146 MW nominal) from battery storage.
Y-4 auction for the 2029–2030 delivery year
For the Y-4 auction for the 2029–2030 delivery year, the initial volume was set at 6,997 MW and later adjusted to 4,694 MW following eligibility corrections – 3,019 MW subtracted and 716 MW added. A total of 69 CRM units participated, offering 4,998 MW, meaning supply exceeded demand. Ultimately, 65 units were selected, totaling 4,690 MW, comprising 4,486 MW of existing capacity, 179 MW (525 MW nominal) of new battery capacity, and 25 MW of refurbished capacity. The clearing price stood at €27.3 k/MW/year, broadly in line with last year’s level.
Elia noted that many battery projects chose to participate in the Y-4 auction (in which capacity is contracted four years before the delivery year under contracts of up to 15 years for new build capacity) rather than the Y-2 auction (in which capacity is contracted two years before the delivery year under one-year contracts). This may be partly due to the less demanding timelines, but these projects are nevertheless expected to become available sooner, contributing to Belgium’s security of supply.
According to Aurora Energy Research’s tally, the dominance of battery storage in Belgium’s procurements is pronounced. Nearly all new capacity contracted in the 2025 auctions came from large-scale batteries – 412 MW in the Y-4 auction, 300 MW in the new Y-2 auction, and 255 MW in the Y-1 auction.
Across all capacity market auctions to date, 1.6 GW of new-build, underated battery capacity has now been awarded capacity payments by the winter of 2029-2030.
Over the past five auction rounds, twenty-one large-scale battery projects secured contracts, with ENGIE, Storm, and GIGA Storage among the main winners.