reason The million-dollar power outages in Spain and Portugal were not fully confirmed on Monday, although services are now restored in 99% of the Iberian Peninsula. Red Eléctrica, a listed company responsible for operating Spanish transmission infrastructure, has ruled out cyber attacks, human errors or abnormal weather or atmospheric conditions due to power outages. The company noted that the incident may have originated from two "disconnections of power generation", which may be related to inherent fluctuations in renewable energy sources.

Experts stress that this type of power outage (which is an unusual and rare event) is also a safety mechanism for the power system itself. In order for the grid to operate stably, energy production and consumption must be kept balanced; imbalances can lead to power outages and potentially damage infrastructure.

Maintaining grid balance is the responsibility of the system operator, who can monitor parameters such as electrical frequency, voltage and load in real time of the substation. When there is a big difference between generation and demand, activation automatically disconnects in specific areas of the grid to avoid imbalance. In the most severe cases, the impact of these triggered disconnects can be extended across the network.

Álvaro Dela Puente Gil, a professor of electrical engineering at the University of Leon School of Mining Engineering, lost more than half of the electric power outages in just five seconds, because more than half of the power generation capacity. "The grid cannot balance power generation and demand so drastically, protecting itself by automatically disconnecting internally and other European grids.

In a comment on SMC, Miguel De Imón Martín, professor of electrical engineering at the University of Leon, explained that balance on the grid is usually guaranteed by three things. First is a complex interconnect network called a grid, which distributes current across the grid to prevent overloading. Second, there is interconnected with the grid of neighboring countries, and energy can be imported or exported as needed to balance power generation and demand.

Finally, there is something called "mechanical inertia". Synchronous generators (large rotary machines that generate electricity in power stations) also store a lot of energy in their very large rotating parts. Imagine, for example, a coal-fired power station. Even if it stops burning coal to generate more power, it is used to generate electricity hugely, the heavy turbine will continue to rotate for a while as it is stored in it. This phenomenon is called mechanical inertia and can serve as a buffer to prevent sudden fluctuations of the grid. When there is an imbalance between energy generation and demand, a synchronous generator can speed up or lower its rotation speed to balance things, thereby filling the grid absorber with electric shock by satisfying or releasing energy.

"A large, good grid with strong interconnections and rich synchronous generators will be more stable and more prone to failure," said Deimón Martín. "The power grid on the Spanish Peninsula has historically been strong and reliable, due to its height and high interaction capabilities, and its greater synchronous capability, its synchronization rate is very high. Geographical obstacles to the Pyrenees."