Brazil's national grid operator, ONS, activated on Sunday (23) an emergency plan to curb a surplus of electricity in the country's interconnected power system (SIN), ordering generation cuts for the second time in 2026. The mechanism, called the Energy Surplus Management Plan for the Distribution Network, is used when power production exceeds what the grid needs.
According to Agência Brasil, the measure was in force from 11 a.m. to 1:30 p.m., with no impact on consumers and affecting only distribution companies. The plan restricts output from so-called Type 3 plants connected to distribution networks — a group that includes small hydroelectric stations, biomass plants and smaller wind and solar farms. The ONS also reduced generation at plants under its direct control and had warned distributors in advance to prepare for the cuts, since it cannot directly command assets connected to their grids.
The intervention stems from the combination of strong output from distributed micro and mini generation — mostly rooftop and small-scale solar systems installed near consumers — and the lower demand typical of weekends. On Sundays and holidays, consumption falls while solar systems keep producing during peak sunlight hours, shrinking the so-called net load, the share of demand that must be met by plants the ONS controls, according to CNN Brasil. The problem, in other words, is not a shortage of power but an excess of it at certain hours.
Second activation of the year
The first activation of 2026 took place on June 7, during the Corpus Christi holiday weekend, when the ONS called for the management of 1,000 megawatts (MW) between 10 a.m. and 2 p.m. The emergency plan was approved in 2025 by the electricity regulator Aneel and is treated as a last resort, triggered only after other options for balancing supply and demand have been exhausted. In August 2025, on Father's Day in Brazil, excess supply nearly overloaded the system: distributed generation came to represent 37.6% of national demand, and the operator cut 98.5% of centralized wind and solar output to avert a blackout.
ONS studies cited by CNN Brasil indicate that installed micro and mini distributed generation capacity in the country has already surpassed 43 gigawatts (GW); Agência Brasil puts the figure at around 50 GW. For the operator, the rapid growth of these sources makes the grid harder to run, because part of the power produced can be neither observed nor directly controlled.
On Thursday (20), the ONS announced it is developing a system to automatically disconnect part of distributed generation in critical situations. Called the Regional Generation Relief Scheme (Erag), the mechanism provides for cuts of up to 3 GW, split into three 1 GW stages, and would only be triggered after all other control alternatives are exhausted. A pilot project is expected at one distributor by the end of 2026, with possible implementation in 2027. The Brazilian association of power distributors (Abradee) said its members will follow the ONS instructions but asked for more detailed criteria for the cuts, in order to give generators operational and legal certainty.