Blackout: report clears Portugal from liability

The technical report on the blackout that hit Portugal on 28 April 2025 concludes that the incident originated in Spain, clearing the Portuguese authorities from any liability and opening a new stage in possible compensation by the national regulator.

The Minister of Environment and Energy Maria da Graça Carvalho presented the report drafted by the European Network of Transmission System Operators for Electricity (ENTSO-E) and validated by the Agency for the Cooperation of Energy Regulators (ACER). The document, drafted by European experts, concluded that the incident resulted from multiple technical factors without legal liabilities being indicated, as that assessment falls on national authorities.

The report included 23 recommendations, of which, according to the Minister "90% […] are already implemented or envisaged for Portugal", namely in terms of voltage control, sharing of data, and boosting the system’s resilience. Among the main guidelines, one notes the strengthening of voltage control and the coordination between production, distribution, and electricity transmission.

"This report confirms that the Portuguese authorities are not responsible for the blackout, nor did they cause it", Maria da Graça Carvalho claimed, stressing that from a technical standpoint, "all [the causes] lie outside Portugal".

The analysis identifies a succession of technical faults that began on Spanish soil, with episodes in Granada, Badajoz, and Seville, associated with insufficient voltage control. The fault spread to the Portuguese system in less than 90 seconds with a collapse that left the Iberian Peninsula in the dark for several hours.

The report acknowledges the event’s complexity and the lack of a single cause, indicating structural challenges in terms of voltage control, the coordination between systems, and the autonomy of critical infrastructures, such as telecommunications.

Given these conclusions, the Government now sends to the Portuguese Energy Service Regulator (ERSE) the assessment of the consequences and the definition of the legal framework for possible compensation, stressing that the event’s extraordinary event may limit severance pay.

"Now is the time for the Portuguese regulator to conduct its assessment and indicate the path to take with regard to compensation", the Minister of Environment and Energy added.