How a battery earns in Spain

Spain runs a single national price zone: Red Eléctrica (REE) operates the grid while OMIE clears the day-ahead market for the whole Iberian system (MIBEL). Record solar and wind — frequently more than half of supply — now collide with a saturated grid: renewable curtailment jumped +110% year on year in 2025 and peaked near 11% in July, after REE tightened security under “reinforced operation” following the 28 April 2025 blackout. That volatility is a battery’s income: the 30-day day-ahead spread averaged €113 /MWh — 119% of the average price. Spain backs storage directly — MITECO’s PERTE grants grew to €840 million across 143 projects (2.4 GW / 8.9 GWh) — and standalone batteries are exempt from grid access fees when charging, so every buy × sell cycle keeps more of that spread.

€113/MWh

day-ahead spread — 119% of the average price (30 days)

€840million

MITECO/PERTE storage grants — 143 projects, 2.4 GW / 8.9 GWh

+110% YoY

renewable curtailment surge in 2025 (peaked ~11% in July)