Six weeks after Spain and Portugal suffered a massive power outage, authorities in Madrid issued an official report Tuesday, saying April’s cascading blackout that left tens of millions disconnected in seconds was caused by technical and planning errors that led to the grid’s failure. Spain’s Ecological Transition Minister Sara Aagesen said Tuesday small grid failures, concentrated in the south of Spain, led to a chain reaction among larger ones, while completely ruling out questions about a cyberattack. The minister said one factor of many in the chain of failures of the system was the poor planning by grid operators to manage oscillations in tension.
