April's electric blackout was caused by "several factors," according to European experts

The electric blackout of 28 April 2025 was the result of "several factors that affected each other."  The new report by theEuropean Network of Electricity TransportNetwork Managers (Entso-E) concludes that  "spread very quickly"   "a local problem"that occurred in southern Spain. Hor caused general disconnections due to overvoltage, and finally lost the synchronization of the Iberian system with the rest of the European territories.

This European study has refused to point out the sole responsibility for the incidentand has stressed that 'electric zero' was theresult ofthe 'association of multiple factors', not of a single major cause, as explained by theresearch director, Klaus Kaschnitz.

Thus, the report concludes that the historical "blackout"of the peninsular electrical system came through a chain of events which, caused by a combination of tension fluctuations and oscillatory phenomena, resultedin widespread disconnections of many sources of generation in Spain, especially in resources based on investors; followed by a chain of disconnection caused by over-tensions ; and, finally, by the loss of synchronism of the Iberian system with the rest of the European system.

In this regard, Board Chairman Damian Cortinas Entso-E has stressed that it was an unprecedented blackout , unprecedented overthe past two decades. "Such an electric zero was not known, but we know it can happen now, and we can draw several lessons from what happened to avoid it in the future," he added.

Thus the event cannot be attributed to a single cause, but was "the mutual action of several factors, all of which produced electric zero."

The problem was originally "a very local problem," which originated in southern Spainand "spread very rapidly," extending to Portugal. "It only stopped in the Pyrenees before extending to the rest of Europe. But at first it was a limited local problem. When we looked at all the factors that caused the blackout, the only non-local was regional oscillations, "he stressed, referring to the two oscillations observed in the half hour preceding the blackout, which occurred at 12:32 that day.

The report also states that, although the system's defence plans were properly activated, "the nature and dimensions of numerous events caused a complete collapse of the Spanish and Portuguese systems in a few seconds ".

With regard to the process of restoring the system after the blackout, he stresses that it began immediately and was restored in 12 hours in Portugal, and in 16 hours in Spain, thanks to 'strict restoration procedures, contingency strategies and the full commitment of all operators, operators, producers and others'.

Along with these conclusions, the report aims, above all, to provide 'clear and practical recommendations', based on lessons left by electric zero, to reduce the likelihood of similar events and to strengthen the security and overall resilience of the European network.

In this regard, it is proposed to strengthen coordination between electrical system operators (transport and distribution operators, large producers and consumers) as key elements in the efficient management of complex situations and the improvement of regulatory frameworks, and it is recommended to optimize operational practices, increase system monitoring and encourage data exchange.