The blackout in Spain, which occurred at 12:25pm (CEST) on Monday (April 28), was caused by a severe mismatch between supply and demand, with the "loss of generation" exceeding the amount of electricity the grid could absorb, according to Spanish grid operator REE.
"At the time of the blackout, 15 GW of generation was suddenly lost from the power system, something that has never happened before," said Spanish Prime Minister Pedro Sánchez.
According to REE, more than three-quarters of the electricity generated during the restoration of power supply came from renewable sources. In the evening, the share of photovoltaic power generation naturally dropped, gas and steam power plants began to operate, and coal and nuclear power plants remained completely shut down.
Sanchez denied that the blackout was caused by a lack of nuclear power, saying in a speech at noon on Tuesday (April 29) that when the accident occurred, "nuclear plants were still operating and then stopped; nuclear plants are not more resilient than other energy sources. What we see is that if there is a greater reliance on nuclear power, the recovery will not be as fast as we are seeing now; in fact, the recovery will be much slower. At present, nuclear plants cannot compete with renewable energy sources due to the decisions of the power generation companies themselves."
Meanwhile, some homes and businesses have never lost power thanks to solar panels and battery-based backup solutions.
Sanchez also said: "The government has two clear priorities: first, consolidate the results of the 100% recovery of the power system. The power system will be operated in an interventional, fail-safe manner, with synchronous power generation. If there are no new developments, full market operations will be restored tomorrow. Second, identify the cause of the accident and take measures to prevent similar incidents from happening again."
REE technicians are still analyzing the system and expect to get results within a few hours or days. Meanwhile, private power generation companies are reviewing telemetry data from their production and management centers to understand what happened in the five seconds that triggered the system failure. The findings will help strengthen power systems and prevent the incident from happening again.
