Brazil’s power grid operator activated an emergency plan on Sunday to balance excess generation and prevent a supply collapse, curtailing 1 gigawatt (GW) of power from distributed plants. The measure, the second such activation this year, was triggered by rapid growth in rooftop solar capacity, which has overwhelmed grid operators during low-demand periods such as weekends and holidays.
The cuts targeted “Type III” facilities, including small hydroelectric plants and biomass thermal power plants, between 11:00 AM and 1:30 PM local time. In parallel, the ONS (Operador Nacional do Sistema Elétrico) disconnected more than 20 GW from large wind and solar farms in the Northeast throughout the day. The national grid load stood at approximately 71 GW during the period.
The emergency response reflects challenges posed by Brazil’s expanding distributed solar sector, which has expanded beyond the grid operator’s ability to manage without risking blackouts. Rodrigo Viga Gaier, one of the authors, noted that the system remains under close monitoring to ensure stability under current operating procedures.
Looking ahead, the ONS plans to begin testing automated curtailments of remote distributed solar generation by year-end, targeting reductions of up to 3 GW from solar farms supplying subscription-based energy services. The initiative aims to mitigate future imbalances as solar capacity continues to grow unchecked.
The grid operator emphasized that its actions are in line with existing network procedures to safeguard system security and efficiency amid a rapidly evolving energy landscape.
