Brazil Curtailed Nearly 20% of Solar and Wind Power in 2025, Losing BRL 6.5 Billion

Image: Volt Robotics

Brazil failed to utilize nearly 20% of the solar and wind electricity it generated in 2025, resulting in estimated losses of BRL 6.5 billion (US$1.1 billion), according to Volt Robotics’ Annual Curtailment Report.

Volt Robotics said the scale of curtailment reflects an unprecedented period of renewable oversupply combined with operational constraints in Brazil’s national electricity system, marking a structural shift in system risk dynamics.

Average generation cuts reached 4,021 MW over the year, equivalent to the monthly output of a large hydroelectric plant. On at least 16 days in 2025, system operation approached the lower technical safety limit — a sharp increase compared with 2024, when only one comparable event was recorded.

Unlike previous years, Volt Robotics said the curtailment events in 2025 were driven by excess electricity supply rather than shortages, highlighting growing challenges in managing Brazil’s rapidly expanding renewable fleet.

Curtailment intensified between August and October, when historically high solar and wind generation coincided with transmission constraints and weaker electricity demand. The report attributed peak losses to a combination of operational limitations, grid congestion, and insufficient system flexibility to absorb surplus power.

Sunday mornings emerged as the most frequent stress point for the grid. Volt Robotics noted that reduced economic activity during weekends lowers electricity demand, while solar generation peaks and is often reinforced by strong wind output. This recurring mismatch leads to network overloads, forced generation cuts, and system operation close to the lower safety threshold.

The report also warned of rising risks to system stability. During the 16 critical days identified, Brazil’s National System Operator classified conditions as severe and implemented emergency measures, supported by the National Electric Energy Agency, including extraordinary generation curtailments.

Volt Robotics cautioned that without structural adjustments, surplus clean energy itself could become a source of operational risk rather than a system advantage.

The economic impact extends beyond immediate revenue losses. Frequent curtailment increases perceived investment risk, raises financing costs, and weakens Brazil’s attractiveness for new renewable energy projects, the report said. Both regulated and free-market projects were affected, with exposure to contractual penalties and the Settlement Price of Differences.

Regionally, Minas Gerais, Ceará, and Rio Grande do Norte recorded the highest levels of curtailed energy, forming what Volt Robotics described as Brazil’s “curtailment triangle.” Southern states experienced significantly lower losses.

According to the report, the situation reflects a structural mismatch between rapid renewable capacity expansion, rising distributed generation, transmission bottlenecks, and tariff structures that fail to adequately signal when electricity consumption is most valuable.