On the morning of Monday 28 April, nothing was out of the ordinary in peninsular Spain’s electricity system. Demand was at normal levels for the time of year, and was being easily met by the total generation capacity available. The day before, the Spanish National Grid Network (REE, Red Eléctrica Española, commercially known as Redeia) had held its usual daily auction to determine which facilities would supply energy over the course of the following day. REE manages electricity distribution in S...