Spain's CNMC backs one-hour delay to first intraday power auction to curb cancellations
Spain's energy regulator says moving the first intraday auction back one hour can stop the session cancellations that have hit power trading since at least August 2026.
Spain's energy regulator CNMC told Montel on Friday (2026-09-18) that pushing the first intraday electricity auction from 15:00 to 16:00 CET would be a "simple and effective" fix for the session cancellations that have been disrupting the country's power market.7
The endorsement carries weight: CNMC is the body that must approve any structural change to auction timing, and market participants have been pressing for a solution for months. Spain passed new rules as recently as Friday (2026-08-07) specifically to prevent intraday auction failures, suggesting the problem had persisted despite earlier regulatory intervention.7,6
Session cancellations impose real costs on participants who need to adjust positions across the trading day. If a session fails, traders either carry exposure into later auctions or forgo adjustments entirely, with potential forced positions at less favourable prices. A one-hour delay would give system operators more time to assess afternoon solar output before the first intraday session opens.
The root difficulty is structural. Wind and solar now account for more than 40% of Spain's total electricity supply, shifting generation profiles significantly across the trading day and creating rapid output swings that strain intraday balancing. Nuclear at 19% of generation in 2024 provides steady baseload but cannot compensate for the real-time volatility that comes with high renewable penetration.2
Ancillary service costs have been rising sharply alongside those imbalances. Those costs climbed "brutally" in February and March 2026, market observers told Montel in April (2026-04-14), and were expected to persist, with energy-intensive consumers facing grid-balancing charges that cut into the savings produced by cheaper renewables-driven wholesale prices.3
Spanish day-ahead power traded at €146.29/MWh on Tuesday (2026-09-22), elevated by European standards and partly reflecting the Iberian peninsula's constrained connections to the wider continental grid. Prime Minister Pedro Sanchez said on Tuesday (2026-05-19) that Spain could not wait another decade for new cross-Pyrenean links, pressing Brussels and Paris to accelerate interconnector projects. Without adequate capacity, Spain and Portugal manage their balancing requirements in relative isolation, amplifying the market impact of any auction failure.1
The April 2025 blackout has kept grid management in the regulatory spotlight. A Reuters report found that grid operator REE's failure to calculate the correct generation mix was one of the factors that prevented the system from handling a generation surge on Monday (2025-04-28), the day millions across Spain, Portugal and parts of France lost power. The incident sharpened pressure for reform throughout the subsequent year.4,5
The Bank of Spain estimated that 2024 wholesale power prices were 40% lower than they would have been had the generation mix remained at 2019 levels, a measure of how far Spain has pushed the energy transition. But lower average prices have not reduced balancing costs. High ancillary charges and volatile intraday sessions have eroded net savings for industrial users.2,3
CNMC's backing of the one-hour timing change narrows the gap between regulatory and market preferences. Yet Spain's reform record this year suggests momentum does not always carry through to implementation: the Pyrenees interconnector push and the August (2026-08-07) anti-cancellation rules both show the distance between stated intent and enacted change. The next test is whether formal rule-making follows before the autumn demand upturn sharpens balancing requirements again.1,6