Brazil's Grid Operator ONS Cuts Power Generation Amid Excess Supply

The National Electric System Operator (ONS) in Brazil activated an emergency management plan for the first time to curb excess electricity generation during the long Corpus Christi weekend. The plan, approved by the National Agency of Electrical Energy (ANEEL) in 2025, called for a reduction of about 1,000 MW between 10 a.m. and 2 p.m., a volume enough to power roughly 2‑4 million customers.

Twelve distribution companies—including CPFL Paulista, Cemig, Energisa MT, Copel, Elektro, Equatorial Goiás, Energisa MS, Neoenergia, Coelba, RGE, and others—were instructed to curtail generation from small hydro (PCH), biomass, and low‑capacity wind and solar plants. The action aimed to balance the surge of distributed solar generation that often coincides with lower industrial demand during holidays, preventing instability in the national interconnected system.

The emergency measures reflect ongoing challenges as Brazil’s generation mix becomes increasingly decentralized, with previous incidents such as the Father's Day 2025 event where distributed solar supplied over 37 % of national demand.