April 2026 Spain BESS Forecast update: ancillary floors lift revenues as day-ahead tightens
April 2026 Spain BESS Forecast update: ancillary floors lift revenues as day-ahead tightens
Modo Energy's April 2026 Forecast release is out. Spanish standalone battery revenues now exceed those in the January release across the 2028–2040 horizon. Day-Ahead revenues rise versus Jan-26 before 2030, then fall below it, while ancillary services and continuous intraday revenues now use an updated floor methodology.
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Key takeaways — written by Ko, Modo Energy's AI Analyst
- Total revenues sit above Jan-26 throughout 2028–2040: A 4-hour standalone battery earns ~225 k€/MW/year in 2028 (vs ~190 k€/MW/year in Jan-26), with the gap holding even as both trajectories decline.
- Ancillary + intraday floor is higher post-2030: Close-to-delivery market revenues still compress, but continuous intraday partially offsets aFRR and aFRRE saturation.
- Central case keeps more nuclear online in the long term.
The central case in the April 26 release keeps more nuclear online
Following the latest news on Almaraz's closure schedule, we've revised our Central scenario for Spain's nuclear fleet.
Almaraz I and II close one year earlier than in our Jan-26 release. Almaraz I now retires in 2030 (vs 2031 previously), with Almaraz II following in 2031. As a result, installed nuclear capacity drops to 6 GW one year sooner than previously projected.
But the long-term nuclear fleet shrinks less than before. We now expect installed capacity to settle at 3 GW from 2036 onwards, one reactor (~1 GW) more than in our January forecast. The reason is grid stability: as renewable penetration rises, the Spanish system needs firm baseload to balance the grid, and the three Catalan reactors (Ascó I, Ascó II, and Vandellós II) are best positioned to provide it.





