The challenge of restoring the Spanish electricity system from a total blackout

Many Spanish sports fans remember a legendary cry, "Try to start it, Carlos!" It was uttered by Luis Moya, co-driver of Carlos Sainz Sr., on November 4, 1998, when, 400 meters from the finish line of the Rally of Great Britain, his Toyota Corolla stopped dead due to an oil leak, effectively destroying his chances of winning what would have been his third World Rally Championship title.

Moya's desperation as he begged his driver to get the Corolla moving again was paltry compared to what must have happened at Red Eléctrica in Madrid on Monday, April 28, at 12:33:16 p.m.

At that moment, an incident (still unidentified) caused a frequency fluctuation in the grid. All alarms were activated in the company's Electrical Control Center, where the system's operation is monitored. The protocol is well known to technicians. This isn't the first time this has happened, nor the first time the grid has been stabilized, as happened on Monday. But this time there was no time for euphoria. Barely 1.3 seconds after that first event, a second fluctuation triggered all security systems, and the system's control screen offered information that until that moment had never been thought to leap from virtual simulators to harsh reality: all of Spain and Portugal were in darkness.

At that moment, it mattered little what, who, how, or where the source of the situation lay. The main objective was to "try to root it out." The theory so often reviewed in training courses had to be put into practice.

REE coordinated the energy companies to allow the orderly entry of the different technologies

The spark to achieve this could only come from where there was power. "At 12:44 p.m., the disconnection with France was already being restored," explain sources from the Ministry of Ecological Transition. The first energy input arrived through Irún. At 1:04 p.m., Morocco's electricity injection arrived: 519 MW, 38.71% of its instantaneous grid capacity. Although it was only 5% of what Spain needed, it was enough to activate the system. At 1:07 p.m., the first load was restored to the Spanish system, barely half an hour after total zero.

Of course, ordinary citizens were far from returning to normal. But from that moment on, the arduous task of restoring an entire grid that, before the blackout, was demanding 25,180 MW, began. “The process could be compared to an orchestra, although the musicians, rather than being in the same place, play from very distant positions, always under the orders of the conductor, who is the control center of Red Eléctrica,” explains one of the experts consulted.

The key is to match demand as closely as possible with the energy entering the grid. This estimate must be made by REE, but must be implemented by generating companies.

As Iberdrola Chairman Ignacio Sánchez Galán told analysts, "our fleet was ready and available to the system operator to begin work as soon as we received their instructions." And Iberdrola, as one of the leading hydropower companies in Spain, was undoubtedly one of the first to receive the order to act. The operation of electric pumped storage plants, the most efficient backup technology for the system, "is almost automatic," these sources explain. Like Iberdrola, Endesa, Naturgy, and Acciona, as large generators, were under the regulator's orders. "Then islands are generated around the hydropower plants, which are expanded and joined together until the entire skeleton is created," explains REE.

International connections were key to the reactivation of the system in Spain.

Secondly, all combined-cycle owners were asked to start these facilities at a starting point, something like "idle." A process that takes about 30 minutes, but from which they can then increase their generating capacity by 20% in just one minute. This acceleration occurred as REE technicians instructed. "Those who were active before the blackout took less time to start." From that moment on, they joined in. "In the energy system, everything must be perfectly adjusted. If you put in more energy than is required at a given time, you have a problem again," explain technical sources consulted. Added to this is the fact that, just like when you press the accelerator in a stalled car, it doesn't always start on the first try, or if it does, it stalls again. "This happened quite a few times on Monday." Despite this, in less than 24 hours, almost 100% of the system was operational again. A complete success compared to other events outside of Spain, as the European Network of Electricity Operators (Entso-E) itself acknowledged yesterday.