Electrical System Operator states that agent will control and reduce risk of transmission failure by 2028 because of overload
The executive advisor of the Planning Directorate of ONS (National Electric System Operator), Sumara Duarte Ticom, said on Wednesday (2.Jul.2025), during session of the House Commission of Mines and Energy, that Brazil’s electricity transmission network needs to be supervised by an autonomous agent to avoid overload and transmission failure.
“There are points in the electrical system where there is a transmission reversal that can bring some equipment overloads and we will need to create actions to avoid and resolve, such as increasing the controllability and management of electricity generation so that the flow stops leaving the distribution network. Supervision is done by an autonomous agent.”he said.
In February, ONS released a technical note informing that 11 states would be in 2028 because of the production of electricity by photovoltaic panels. The agent would work to prevent the scenario from materializing, according to Ticom.
After publication, the ONS stated that the document does not point out imminent blackout risk, but evaluations of the electrical performance of the SIN (National Interconnected System) in a 5 -year horizon ahead, so that future operation occurs with quality and balance between safety and cost.
The Commission of Mines and Energy would have a session at 4 pm on Wednesday, to understand the risk of overload in the electrical system, at the request of the deputy (PSD-RJ), but chose to hear the spokesman at the session he held earlier, at 11am, to vote legislative propositions.
The congressman stated that Congress “You need to understand the real risks of a possible overload”.
“Such information, if proceeding, increases, even more, the concern about the constant blackouts that our country has faced in recent years, causing numerous social, economic and public safety losses.”declared the congressman to request the hearing.
Reverse flow
The risk exists because when the energy generated by the solar panels is not used, it enters a “reverse flow” in the electrical system. The traditional path of electricity was unique: from the great generators to substations to the end consumer.
Now, the surplus energy produced by MMGD (micro and distributed minigeing) returns to the transmission system. This creates a two -way road and a risk of overload in the substation. Overload can cause blackout dropping to the system.
MMGD is the production of electricity by small systems, such as solar panels, installed near the place of consumption, with the possibility of injecting the surplus into the power grid.
According to ONS studies, there are 11 states at risk of overload:
- Bahia;
- Goiás;
- Mato Grosso;
- Minas Gerais;
- Paraíba;
- Pernambuco;
- Piauí;
- Rio Grande do Norte;
- Rio Grande do Sul;
- Rondônia;
- São Paulo.
ONS states that the study does not mean eventual “Public calamity” caused by overload. But that attention to the risks of reverse flow in the system needs attention and better supervision.
Absollage (Brazilian Association of Photovoltaic Solar Energy) states that photovoltaic energy does not take risks of overload caused by MMGD. The entity also refuted the thesis that the energy produced by solar panels impairs the transmission lines.
In the view of ABSOLAR, MMGD “It helps to strengthen and bring more resilience to the power grid by bringing electricity generation closer to consumer places.” In this context, pressure on water resources and transmission and distribution infrastructure would be relieved, while power loss in long distances would also be reduced.
