Brazil Faces Record Renewable Energy Curtailment Amid Rapid Distributed Solar Growth

In 2025, Brazil wasted approximately 20.6% of its solar and wind power, equivalent to nearly ten months’ generation from the Belo Monte hydropower plant. This historic level of curtailment stems from operational cuts mandated by the National System Operator (ONS) to prevent grid overload during low demand periods, particularly midday and weekends when solar output peaks while consumption declines. The phenomenon is exacerbated by the rapid growth of distributed generation, primarily residential solar panels, which has surpassed 42 GW of installed capacity and is expected to reach 50 GW by 2028. This surge strains transmission networks, especially in the Northeast, where infrastructure has lagged generation capacity expansion.

Operational constraints force the system to curtail renewable output exceeding network absorption capability, leading to reliance on costlier and more polluting thermal generation during nighttime hours. Data from Volt Robotics and industry reports indicate curtailment accelerated notably after the 2023 nationwide blackout, with the number of days operating near maximum capacity due to excess energy rising sharply from one day in 2024 to sixteen in 2025. Transmission inadequacies are compounded by the geographic mismatch between abundant renewable resources in the Northeast and concentrated demand in the Southeast, highlighting chronic bottlenecks in evacuation capacity.

The cumulative economic impact includes direct revenue losses estimated at over R$6 billion in 2025, with investors increasingly hesitant amid regulatory uncertainties and diminishing project viability. Several renewables developers have withdrawn or canceled projects citing high curtailment rates, transmission constraints, and rising financing costs. Although reforms introduced in late 2025 aim to partially compensate affected generators and incentivize demand during surplus periods, industry analysts stress that without substantial investments in grid modernization and large-scale battery storage, curtailment rates could triple by 2035. Wood Mackenzie forecasts average curtailment of 8% nationally over the next decade, reaching 11% in the Northeast submarket. Battery deployment and enhanced transmission lines post-2030 are critical to stabilizing the system.

Brazil’s position as a leading renewable energy hub depends on overcoming these grid limitations to fully harness its significant clean energy production capacity and avoid turning green energy abundance into operational inefficiency and financial waste.