Blackout in the South and Southeast was deliberate; relief scheme explains cutting

Despite the government claiming that the possible origin of the blackout on Tuesday (15) was a problem in the Northeast, the electricity ended up also being cut off in the South and Southeast. The interruption in the supply of these two regions was deliberate.

The person responsible for the cut was a mechanism known as the regional load relief scheme (Erac), adopted by the National Electric System Operator (ONS) on occasions like this to avoid an even bigger blackout. “The interruption in the South and Southeast was a controlled action to prevent the occurrence from spreading”, the ONS said in a note.

In the relief scheme, whenever stronger variations are detected in the electricity frequency, previously established loads are disconnected in a staggered and automatic way.

The associate researcher at the Federal University of Rio de Janeiro (UFRJ) and director of the Ilumina Institute, Renato Queiroz, compares Erac to a system of circuit breakers, with the function of providing protection and preventing an eventual problem from spreading in a “domino effect” .

The mechanism is computerized. Queiroz explains that, once an irregularity is found, the disconnection of loads in areas close to the problem begins. The situation is expanded if necessary and, after solving the problem, the load is resumed. “It’s a smart system,” he says.

Experts heard by “Agência Infra” pointed out that there would have been an operational problem in the Northeast. More wind energy would be circulating in the networks, but there was a problem in the system, not yet disclosed. The Minister of Mines and Energy, Alexandre Silveira, said that it would have been in Ceará, without giving further details.

The Erac was triggered and dropped the load in the Northeast and in part of other regions, acting to avoid a collapse in the National Integrated System (SIN), which could cause a bigger and more widespread blackout. About 19,100 megawatts (MW), or 26% of consumption at that time, “dropped” during the blackout.

This way of operating is related to the continental dimension of Brazil, which requires transmission lines of thousands of kilometers. The country has advantages and disadvantages with this system.

In cases of energy shortages in one region, for example, the surplus produced in another can help supply.

On the other hand, a disturbance in a given location can cause shutdowns thousands of kilometers from the source, even affecting regions that are large generators of energy – the case of Paraná, where Itaipu is located, or the border between São Paulo and Minas, where Itaipu is located. the Furnas complex.

Doubts remain and there are no answers about the blackout

More than 30 hours after the blackout, many questions remain. The main one is about what would have led to the power cut, which lasted longer in the North and Northeast. The problem started at 8:31 am on Thursday and was only fully resolved at 2:49 pm, according to the ONS.

“We have never gone so long without knowing the origin of a blackout”, said Luiz Eduardo Barata, former director of the ONS, to “Folha de S.Paulo”.

A number of hypotheses were raised. In addition to the problem in Ceará, mentioned by Silveira, the vice president, Geraldo Alckmin, mentioned a failure in a substation in Imperatriz (MA). Problems at the Santo Antônio hydroelectric plant (RO) and at a substation in Anapu (PA), close to the Belo Monte power plant, also became public. The Minister of the Civil House, Rui Costa, said it was a “technical error”, without pointing out which one.

The power outage occurred at a favorable moment for the sector. Reservoirs are full and consumption is below historic peaks.

Demand, meanwhile, is more behaved, notes Queiroz, from UFRJ. The economy is slowing down and the performance of the industry, which is a major consumer of energy, is weak. The sector’s physical production fell 0.3% in the first half compared to the same period in 2022, points out the Brazilian Institute of Geography and Statistics (IBGE).

One aspect to be considered, according to independent energy consultant Rafael Herzberg, is that it is something beyond the control of consumers. An alternative is the implementation of local emergency power generation systems to mitigate the risk of blackouts.

A source heard by the newspaper “Valor” said that a failure in Ceará would not have the power to bring down an entire system. Silveira said, at the press conference held this Tuesday, that it would have been at least two concomitant problems that caused the problem. He did not rule out the possibility of sabotage and said that the Brazilian Intelligence Agency (Abin) and the Federal Police were summoned to investigate.

Another problem raised by specialists and that may have contributed to the blackout is the issue of governance in the sector. Queiroz said that there is a lack of better management in the electricity sector, which is extremely complex and has a direct impact on people’s daily lives. “It is a sector that has a lot of companies involved. There are communication issues,” he says.