The installed capacity of distributed micro and mini-generation, driven largely by rooftop solar panels and small solar arrays, has surpassed 50 gigawatts (GW) in Brazil. That volume accounts for nearly a fifth of the country's total power generation capacity, currently estimated at approximately 260 GW. The swift rollout of photovoltaic panels, stretching from residential rooftops in metropolitan São Paulo to rural properties across the São Francisco river basin in Minas Gerais and Bahia, has accelerated Brazil's clean energy transition while confronting transmission and distribution grids with an unprecedented stress test.
According to an analysis by economist and former director of the National Electric Energy Agency (Aneel) Joisa Dutra, published in Folha de S.Paulo, actual solar generation is higher. A technical report from the National Electric System Operator (ONS) estimated that unregistered solar systems operating without formal utility authorization in rural and peri-urban circuits of states like Goiás and Mato Grosso added up to 14.6 GW in unmonitored capacity in 2025.
Emergency curtailment and relief mechanisms
The surge of midday solar power, particularly during weekends and national holidays when industrial power demand drops, creates localized oversupply and threatens grid stability. To prevent blackouts and protect electrical equipment, ONS triggered emergency curtailments on connected distributed generation plants in recent days. The operator previously used the mechanism during the Corpus Christi holiday earlier this year.
To manage persistent oversupply, ONS is preparing to test the Regional Generation Relief Scheme (ERAG) later this year. The automated protocol will step down or disconnect output from remote solar farms in a tiered fashion during severe grid imbalances. The system adapts the operational logic of Brazil's longstanding load-shedding scheme (ERAC), used historically to stabilize urban power supplies during transmission failures.
Tariff imbalances and regulatory reforms
Beyond the technical hurdles of physical grid balance, rapid decentralized expansion exposes structural economic imbalances. Energy economists highlight that current net-metering structures shift a growing share of fixed grid maintenance costs and sector subsidies onto conventional consumers, disproportionately affecting lower-income households and renters who lack the capital or roof space to generate their own power.
To keep the clean energy transition equitable, regulators at Aneel and regional utilities are exploring revised tariff structures, dynamic time-of-use rates, and incentives for utility-scale battery storage across regional substations, measures designed to maintain reliability as clean power expands across the national territory.