The large blackout: could an excess of renewable energy break down the Spanish electricity grid?

The previous day, Spanish Electric Electric established procedure– What structures would provide energy at each hour the following day. Ree, the electricity manager in Spain, is an independent company of companies that generate electricity. His web He says “We guarantee a continuous, safe and high level of quality electricity at all times and throughout the national territory”.

12:30 hours: renewable power supply The system

Around 12:30 in the morning most of the demand was covered with renewable sources, in particular photovoltaic solar energy, which contributed with just over half of the total. This phenomenon has been repeated throughout the month during the maximum hours of sun radiation, hitting directly At the price of light.

At that time, Spain exported electricity to Morocco, Portugal and even France. In addition, the large amount of energy was used to pump the water from the lower parts of the basins to the water basins, which is the only practical way to keep energy on a large scale. However, this ability has a margin and, with practically full tanks, it cannot be stored indefinitely.

12:33 hours: something strange happens

In the five minutes passing between 12:30 and 12: 35h. something anomalous, even without official explanations: it occurs A sudden fall in Iberian electricity. In the first minutes the confusion reigns, accentuated by the interruption of fixed and cell phone networks.

The voice circulates even that other European countries could be affected (which I hear within battery radius) and the hypothesis of a possible computer attack is raised. It is surprising, since the usual thing is that the computer networks that control the electrical systems are disconnected from the Internet.

After a few minutes, it is confirmed that the blackout was limited to the Iberian peninsula. This strengthens the idea that the most probable cause is a technical failure in the management of the network.

Analysis of the situation

When analyzing the data available between 12:30 and 12:35, several unusual events are observed. The regulation – the mechanism to balance the offer and demand – was mainly carried out with hydraulic energy. Something normal. However, a point has arrived where this source has exhausted its adjustment capacity.

At the same time, there has been a rapid increase in the generation of the wind which, added to the plot, caused greater injection of electricity in the network. In addition, France has stopped importing electricity from Spain, aggravating the imbalance between supply and demand.

At that time, the nuclear power plants, which operated in the middle of their normal capacity, as expected, received a signal of overload. And according to the protocol, the control bars have been automatically disconnected.

The most surprising thing was the behavior of photovoltaic solar energy, which abruptly went from the generation of 18,000 MW to only 8,000 MW. Even if, evidently, the sun had not disappeared.

The keys indicate a problem in the synchronization of the network (all sources that provide energy to the network must be synchronized at the same frequency, 50 owners). To facilitate this synchronization, a stable basic energy is needed, which normally provides nuclear and large structures. But at that time there was little base of stable sources and, moreover, the nuclear power plants operating had been disconnected from the overload in the network. In this case, as we have seen, the overload produced the excess offer.

The diagnosis

This rare situation indicates possible failures in which, probably, the computer programs responsible for managing these events played an important role, which perhaps did not correctly contemplate a situation like the one that has occurred. An important factor to correct in the future is the small connection we have with the European network through France.

A more worrying substantial cause is the weight of political management in the ree. Although it is formally a private company, the state has 20 % of its capital. Traditionally, its presidency has been occupied by former ministers or high political positions, but it is essential that important technical bodies such as Ree are directed regardless of staff with adequate technical training.

Another sentence to be indicated was the participation of nothing that occurred in the communication of the emergency to the technical staff of Ree, which are those who have the deepest knowledge of the system.

A situation like the current one can be repeated. It is essential that political decisions, such as the entire renewable, have an independent technical support that analyzes and rigorously reports and transparency to citizens.

Fortunately, at the time of the publication of this article, the electrical system was recovered in its entirety. We must take measures so that a situation like this no longer happens.

J. Guillermo Sánchez LeónUniversity Institute of Fundamental Physics and Mathematics (Iuffym), University of Salamanca

This entry was originally published in The conversation. Read the original.