Madrid AP  —  Spain’s government said Tuesday that the massive April power outage across Spain and Portugal that left tens of millions of people disconnected in seconds was caused by technical and planning errors that left the grid unable to handle a surge in voltage. Ecological Transition Minister Sara Aagesen, who manages the nation’s energy policy, told reporters that a voltage surge led to small grid failures, mainly in the south of Spain, which then cascaded to larger ones and brought the