As Brazil accelerates its transition to renewable energy sources, the rapid expansion of wind and solar power has inadvertently introduced significant challenges to the nation’s electricity grid, raising concerns about reliability and potential blackouts. The situation highlights a critical need for strategic planning and infrastructure improvements to ensure that Brazil’s energy transition does not come at the expense of stability.
The reliance on renewable energy, particularly wind and solar, is essential in combating the climate crisis. However, as energy expert Luiz Barata notes, “too much excess causes problems.” Brazil’s electricity system, one of the most complex in the world, is struggling to manage the increased unpredictability associated with a growing number of renewable sources. This complexity stems from an interconnected national grid that has evolved from a reliance primarily on hydropower to a more diverse energy mix that includes intermittent sources.
A significant wake-up call occurred on August 15, 2023, when a blackout affected 27% of the country’s electricity supply, affecting most regions. This incident originated from the overloaded wind and solar power plants in Ceará, a northeastern state. Similar close calls were reported in April and August of this year, underscoring the urgent need for better management and planning, according to the National System Operator (ONS).
A well-functioning electrical system requires a balance of supply and demand, and Barata, a former ONS director, emphasizes that surpluses are necessary. However, the unchecked increase in renewable generation is leading to operational difficulties. The shift toward distributed generation—where consumers generate their own electricity through residential micro-plants—has also added complexity. With 3.8 million micro-plants producing over 43 gigawatts of power, this decentralized energy generation accounts for 18% of Brazil’s total generating capacity, predominantly from solar photovoltaic sources.
The unpredictability of wind and solar energy poses challenges in matching generation with consumption patterns. The ONS has had to curtail contributions from these sources during periods of excess supply, predominantly impacting wind and solar generation that are located far from the areas of highest demand. The Northeast, rich in renewable resources, contrasts starkly with the Southeast, Brazil’s most populous region, where energy consumption is highest.
Barata warns that the expansion of distributed generation is likely to worsen operational issues within the electricity system, as it continues to grow without adequate planning. Between January and August 2025, ONS reported that 17.2% of potential wind and solar generation was discarded—equivalent to 7% of the country’s monthly consumption. This figure represents a threefold increase in cuts compared to the same period in 2024, with August alone seeing 57% of new renewable generation rejected due to oversupply.
Brazil’s energy landscape is shifting dramatically. While hydropower still dominates, accounting for 46.5% of the total installed capacity as of the end of 2024, its share has declined significantly from 89% in 2000. Solar energy now represents 20.5%, wind energy 12.5%, and thermal energy 18.6%. The trend indicates a growing move towards renewable sources, but the accompanying regulatory frameworks have not kept pace with this transformation.
Barata advocates for comprehensive structural reform within the energy sector to address these challenges. While the expansion of renewable energy is crucial, existing legislation and regulations need to adapt to mitigate risks and enhance operational conditions. Joilson Costa, coordinator of the Front for a New Energy Policy for Brazil, adds that attributing systemic risks solely to excess wind and solar generation oversimplifies the issue. He highlights the deficiencies in the transmission system that prevent the effective transport of energy produced in the Northeast to other regions during critical times.
Distributed generation is not entirely devoid of planning considerations. The Energy Research Company, part of the Ministry of Mines and Energy, incorporates this modality into its forecasts, even if the growth of micro-plants is not directly controllable. Electricity distribution companies are also actively monitoring the evolution of distributed generation and can update their data monthly.
One of the most troubling aspects of this transition is the mismatch between generation and consumption patterns. Solar energy peaks during the day when demand is lower, while wind energy often generates more power at night when consumption decreases. This daily asynchrony complicates the management of supply and demand, with the ONS estimating that by 2029, it may oversee less than half of the country’s installed generation capacity, further increasing operational uncertainty.
The Brazilian government is exploring solutions such as promoting digital data centers to help balance electricity consumption. These centers could absorb excess energy during the day while increasing nighttime demand. However, this shift presents its own risks, especially with the rise of electric vehicles, which could further strain the grid.
As Brazil grapples with the consequences of a fast-tracked transition to renewables, the stakes are high. The country must find a way to embrace clean energy while ensuring that its electricity system remains resilient and reliable for all citizens. Without a concerted effort to address planning and infrastructure needs, the promise of a green energy future could be overshadowed by the threat of blackouts and operational chaos.
