The blackout on 28 April exposed structural weaknesses in the stability of the Spanish electricity system and triggered a domino effect on the market’s regulated costs.

In conversation with Strategic Energy Europe, Aníbal Martín Rolla, CEO & Founder of Febo Energía, warns that the sharp increase in Ancillary Services and Technical Constraints prices is forcing electricity suppliers to rethink their contractual frameworks, introducing new adjustment clauses that are straining relationships with industrial consumers.

The 28 April blackout not only disrupted electricity supply across much of the country, but also caused a shockwave in the electricity market, pushing suppliers to review their contracts in response to a sudden spike in regulated system costs, particularly in Ancillary Services (SSCC) and Technical Constraints (RRTT).

According to industry data, in the days following the incident, Red Eléctrica Española (REE) increased the activation of ancillary services to reinforce system stability, which in turn drove up the associated costs. While SSCC costs typically hovered around €13/MWh, they exceeded €30/MWh, with some early May figures already approaching €35/MWh.

In response, many suppliers are introducing adjustment clauses into their fixed-rate contracts. These clauses allow for monthly adjustments to the final price if real system costs surpass specific thresholds—typically in the €10–15/MWh range. The adjustment is calculated based on the customer’s actual consumption, corrected for losses.

“For suppliers, offering fixed prices based on outdated parameters is no longer viable if these costs spiral out of control,” says Rolla. However, while this practice is justified as a means of maintaining economic sustainability, it is creating unease among some industrial clients who opted for fixed contracts precisely to avoid volatility.

The CEO of Febo Energía also warns of potential user vulnerability if these clauses “are not communicated with sufficient transparency”. Meanwhile, REE has explained that the cost increases are due to the need to strengthen technical reserves in the aftermath of the system collapse.

This episode has highlighted that the Spanish electricity system is undergoing transformation. Suppliers are adjusting their strategies, clients are revisiting their contracts, and the market is entering a new phase of regulatory and operational uncertainty.