ONS Activates Emergency Plan to Cut Local Generation

Overview

• The Operador Nacional do Sistema Elétrico put the Plano Emergencial de Gestão de Excedentes into operation for the first time on Sunday to stop a supply surplus from destabilizing the national grid.
• ONS first asked large, centrally controlled plants to reduce output and then instructed distribution companies to cut generation inside their concession areas because small plants and rooftop solar are not directly controlled by the operator.
• The measures targeted so‑called usinas Tipo III and mini and micro generation that sit on distribution networks, a group that includes small hydropower, biomass and rooftop solar feeders.
• Distribution firms and their trade group Abradee said they executed the required cuts but asked the operator for clearer, detailed procedures to avoid legal and operational uncertainty for companies and small generators.
• The activation follows a near collapse on Father’s Day 2025 when rooftop solar briefly met about 37–40% of demand, and it highlights longer‑term needs for storage, grid services and clearer rules to manage growing distributed renewables.