The recent blackout in Spain and Portugal started with the loss of electricity production in power plants with a total capacity of 2,200 MW in the south of Spain, according to an update from the European Network of Transmission System Operators for Electricity (ENTSO-E).
ENTSO-E published the sequence of relevant events from the incident on April 28, which caused a total blackout in Spain and Portugal. The system was fully restored after 16 hours. A small area in France, close to the border with Spain, was also affected by the incident, albeit for a very limited duration, the organization said.
At the end of 2024, Spain’s installed capacity for electricity production was 129 GW or 129,000 MW.
It was one of the most serious incidents so far, on a European scale, and the second one in just ten months in the Continental European Synchronous Area, formerly known as UCTE. It includes most of the European Union as well as Turkey and Southeastern Europe. The first blackout, in the Balkans, occurred on June 21 last year.
ENTSO-E and its member transmission system operators (TSOs), the EU Agency for the Cooperation of Energy Regulators (ACER), national regulatory authorities (NRAs), and regional coordination centers (RCCs) have set up a joint expert panel to investigate the event.
During the half hour before the incident, two periods of power and frequency swings were observed in the Continental European Synchronous Area
The blackout was the result of a complex sequence of events, ENTSO-E said. It published a preliminary chronology.
During the half hour before the incident, two periods of power and frequency swings were observed in the Continental European Synchronous Area, between 12:03 and 12:07 and between 12:19 and 12:21, respectively.
“The TSOs of Spain (Red Electrica) and France (RTE) took actions to mitigate these oscillations. At the moment of the incident, there were no oscillations and the power system variables were within normal operation range,” the update reads.
Data so far has yielded the following sequence of events during the incident:
- Starting at 12:32:57 and within 20 seconds afterwards, presumably a series of different generation trips were registered in the south of Spain, accounting for an initially estimated total of 2,200 MW. No generation trips were observed in Portugal and France. As a result, the frequency decreased and a voltage increase is observed in Spain and Portugal.
- Between 12:33:18 and 12:33:21, the frequency of the Iberian Peninsula power system continued to decrease, touching 48 hertz. The automatic load shedding defense plans of Spain and Portugal were activated.
- At 12:33:21, the alternating current overhead lines between France and Spain were disconnected by protection devices against loss of synchronism.
- At 12:33:24, the Iberian electricity system collapsed completely, and the high-voltage direct current (HVDC) lines between France and Spain stopped transmitting power.
As soon as the disruption of the electricity supply occurred, the affected TSOs worked together in a coordinated effort to restore power in the affected region of France, as well as in Spain and Portugal.
The restoration process in Spain was finished at 4:00 on April 29
The restoration process started at 12:44 on April 28 and finished at 4:00 the following night. The restoration of the system was initiated by a black start of hydropower plants in Spain and Portugal.
The restoration process of the transmission grid in Portugal was completed at 00:22, data showed.
According to ENTSO-E, the investigation will be split into two phases. First, the panel would collect and analyze all available data on the incident to reconstruct the events of April 28 and determine the causes of the blackout. The insights would be completed and published in a factual report.
In the second phase, for the final report, the panel is tasked with establishing recommendations to help prevent similar incidents.
ENTSO-E was also in charge of the investigation of the Balkans blackout. The organization published the final report in March.
It Is incredibile that After 14 days from the incident we don’t know the exact sequence of main parameters ( frequency,voltage, sequence of Powers plants disconnected from the grid, sequence of main lines disconnection) during the iberian relevant minutes of black out.It Is like all oscillopertorbographs are other systems normally installed in Electric systems or Power plants, not installed in Spain.When in September 2003 there was the black out in Italy,due to a main line disconnection with Swiss, After two days It was clear the exact sequence of grid problems and the reasons that determine the incident.Really It Is inusual what now It Is unclear in Spain and Portugal event.