The electrical system must work in real time, balancing the energy it produces with the existing demand to avoid collapses. Credit: Raul Varzar.
FRANCESCO RODELLA | Tungsteno
On the morning of Sunday, June 16, Silvia Legler, 54, from Argentina, flicked on the light switch when she woke up. It didn’t work. She found this strange and asked her sister Laura if there was electricity in the hardware store they run together in Pinamar, four hours from Buenos Aires. She replied that the power was out throughout the country. "I thought she was pulling my leg. Something like that had never happened before." Indeed, that day almost all of Argentina, Uruguay and some areas of Paraguay suffered a general blackout that took hours to recover from. Why did something like that happen? Could the same thing happen in other countries? Are we prepared for this eventuality?
The Argentine government, whose energy secretary Gustavo Lopetegui on that same day described the blackout as an "extraordinary event that should not have happened and should not happen again," did not have an easy time explaining it. He finally did so on July 3, when Lopetegui assured the Senate that the national electrical system collapsed due to a chain of failures that occurred over 30 seconds at 7:06 a.m. local time. It took more than 14 hours for the situation to return to full normality.
According to the Argentine government, as reported by the country’s main newspapers, La Nación and Clarín, the blame for the blackout lies squarely on Transener, the private/state-owned company responsible for transmitting energy. There was a short circuit in a specific line of the network, which caused an imbalance between the demand at that time (which was already low because it was a Sunday morning) and the amount of energy produced. At that moment, there was a technical error on the part of the transmitter that prevented this imbalance from being properly limited, leading to the blackout, Lopetegui concluded.
However, added Lopetegui, the failure should have affected only a part of the network, and if it spread throughout Argentina (with the exception of some areas in the far south) and beyond, it was because there were later failures due to incorrect actions by some generators and most of the distributors. The damage that occurred affected millions of people.
Electric systems, increasingly automated, should anticipate the possible increases in demand due to the growth of digital technologies. Credit: American Public Power Association.
Are we all at risk of such a brutal blackout?
Manuel Alcázar, professor at the Polytechnic University of Valencia, explains that at the root of everything is the need for the electrical system to always work in real time, in other words, the energy produced at a given moment must correspond exactly to the consumption demand at that moment. This is mainly because current technology does not allow us "to store electricity in large quantities cheaply," he explains.
The balance has to be constant. "The moment there is an anomalous situation in that coordination, there may be a problem." To avoid serious problems, he maintains, the electrical systems are usually based on a "redundancy" criterion. In other words, they always have at least one extra element, which means that if one component —a generator or a transmission line, for example— fails, the rest of the infrastructure can continue to function.
"Apparently, in Argentina one of the lines was disconnected for maintenance reasons. They didn’t take the precaution of reconfiguring the protection systems accordingly. And by not having that redundancy, as soon as another element failed, the problem was unleashed," Alcázar says. In his opinion, part of the responsibility also lies with the government, which regulates the network. "Probably it has not contemplated all possible eventualities," he says.
A meshed energy transport network as well as a structure not dependent on a few large power plants limit the possibility of a blackout. Credit: American Public Power Association.
The secret lies in having a network interconnected and meshed
Both he and Santiago Arnaltes of the Carlos III University in Madrid, agree that although the possibility of a blackout cannot be 100% ruled out, it would be difficult for something similar to happen in Spain. Alcázar emphasizes that the Spanish energy transport network is very meshed, which means that "if there is a problem for energy to reach consumers through one site, there will always be an alternative way," and that there will be "many security steps." His colleague stresses that "the operators of the network are frequently trained to replace the system in the shortest possible time in the event of a blackout."
The two experts explain that another strong point is that the Spanish system does not depend on a few large power plants, as it does in Argentina, but is interconnected with the rest of Europe. "If there were a problem here, the interconnection with France would quickly be pulled. Therefore, other countries around us could help us resolve an unforeseen situation," says Alcázar. For Arnaltes, protecting that feature is fundamental. "One of the most severe contingencies for Spain would be the loss of interconnection with the rest of the European system," he says.
Both believe that network operators are also prepared for an eventual increase in demand due to the growth of sectors such as digital technologies. "The planning of the system foresees an increase in demand over different time horizons. A calculation error that minimises that growth is not plausible," considers the Carlos III professor. Alcázar, on the other hand, emphasizes that possibilities are being studied to ensure that demand is also sustainable in the long term, for example with the search for greater energy efficiency and a more active and responsible role for consumers.
Nor are these experts particularly frightened by potential cyber threats to increasingly automated and intelligent systems. "Cybersecurity is a major issue today," says Arnaltes, "and the electric companies take this issue very seriously. I would go so far as to say that cyber attacks have very little chance of success," he concludes.
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Tungsteno is a journalism laboratory to scan the essence of innovation. Devised by Materia Publicaciones Científicas for Sacyr’s blog.