Brazil's National Electric Energy Agency (Aneel) announced on April 24, 2026, a yellow tariff flag for May, increasing electricity bills after four months of green flags (January to April). Reduced rainfall has lowered hydroelectric output, requiring costlier thermal plants and adding R$ 0.01885 per kWh consumed.
Aneel cited unfavorable generation conditions, with reservoirs necessitating more thermal plant use. This ends the green flag streak since January 2026, echoing 2025 patterns where green flags shifted to yellow and red by mid-year.
The tariff flag system, marking its 11th year, signals variable costs in Brazil's National Interconnected System (SIN) based on monthly assessments by the National Electric System Operator (ONS). Aneel encourages efficient consumption to minimize waste.
Yellow adds R$ 0.01885/kWh; red flags add more (level 1: R$ 0.04463/kWh; level 2: R$ 0.07877/kWh).
