General electric breakdowns like the one that hit Spain and Portugal on Monday can have multiple causes, but the event already highlights a certain “Vulnerability” of the regional system of the Iberian Peninsula.
Why is the cause not yet clearly identified?
The electrical network is a spine that includes thousands of interconnected components. “Network operators must carefully analyze huge amounts of data in real time”such as frequency changes, line failures, the state of production plants, “In order to trace the sequence of events”explains Pratotheeksha Ramdas, analyst at Rystad Energy.
What are the usual causes?
The breakdowns are often caused by the sudden judgment of a production center due to a technical hazard or a fuel shortage to supply thermal power plants.
In recent years, events such as storms, earthquakes, forest fires, extreme heat or cold, sometimes intensified by climate change, have been able to damage infrastructure or create demand peaks for heating or air conditioning.
Other possible causes: overloads on high -voltage lines, which force excess electricity to move on other lines, and cyber attacks, an increasingly cited threat, due to increasingly digitized networks. Spanish justice has announced an investigation into a possible “IT sabotage”the Sanchez government stressing for its part that « No hypothesis ”is dismissed.
Imbalance between supply and request?
In Spain, Monday evening, the manager of the REE network spoke “A strong oscillation of power flows, accompanied by a very large production loss”. In Europe, the electrical frequency on the network is calibrated at the standard of 50 Hertz (Hz).
A frequency lower than this level means that there is not enough electricity produced in relation to demand; Above, this means that less current must be produced. It is the work of operators to order in real time in the power stations to produce more or less, according to demand, and to maintain the frequency.
“Maintaining this frequency is a question of balance”said to AFP Michael Hogan, advisor for the Regulatory Assistance Project (RAP) organization. If the frequency moves away from 50 Hz, automated protection systems are triggered to cut parts of the network to avoid damaging equipment. Chain disconnections that led to the generalized failure.
“Once the power plants are starting to stop to protect themselves, the situation can quickly become uncontrollable. But it is very rare that it reaches the stage ” Observed Monday, underlines Michael Hogan.
-How all this started?
Difficult to say. “One of the factors that has most likely contributed to instability is the low interconnection between the peninsula and the rest of the Western European network, which means that there was not much inertia in this part of the network to amortize the oscillations” On the Spanish side, according to Michael Hogan.
But it is a possible factor and not the primary cause. “It will probably be the failure of one or two major transmission facilities, which has then spread to other connected parts of the network, but the cause of this initial failure remains to be determined”he adds.
What impact of renewable energies?
In Spain around 40 % of the electricity produced is solar and wind origin. At noon on Monday, it was even around 70 %, at a time of low demand.
However, unlike the gas power plants which “Need a few minutes to start”, “Solar and wind production cannot be controlled on demand and must often be reduced”we underline at Rystad Energy.
The grouping of European managers of electricity transport networks, ENTSO-E, had warned on April 18 of the risks of solar overproduction when approaching sunny days.
A “warning”
Monday failure is a ” warning “Pour Rystad: “Without stronger resilience at the national level and without better regional coordination, future network failures could have even more serious consequences”. “Without sufficient flexibility measurement, such as storage, fast start -up power plants or solid interconnections, high variations in renewable energy production can destabilize the network”explains the analyst Pratrateksha Ramdas.
Critics of renewable energies were immediately broadcast on social networks after the breakdown, but Michael Hogan recalls that giant cuts of this type, in the past, have “Almost always” been caused by transmission problems, not production.
Lion Hirth, professor of energy policy at the Hertie School in Berlin, however estimates « probable » that a system with very little conventional production (nuclear, gas, coal, hydroelectricity) has less amortization inertia, that is to say that it is more inclined to ensure that such oscillations become uncontrollable ”. While remaining cautious, he estimates “That the fact that the Iberian system operated mainly to wind and solar energy on Monday noon did not help”.
