The guarantee that Brazil will not suffer blackouts during severe droughts or extreme heat waves rests today on a technical and environmental paradox that EPE (Energy Research Company) classifies as one of the main challenges of the electricity sector.
In his most recent fact sheetsIn a statement released on Tuesday (30), the state-owned company that oversees expansion planning details that thermal power plants are simultaneously the solution to the intermittency of renewable sources and, at the same time, direct victims of climate change.
While in 2024 these plants met approximately 14% of the national load, in years of acute water scarcity, such as in 2021, the demand on the thermal power plants jumped to a level 35% higher, demonstrating that the system is deeply dependent on this source to maintain the balance between supply and demand.
One of the issues raised by EPE, however, is that this "anchor" of energy security is losing efficiency precisely when the country needs it most.
Among other threats, rising global temperatures reduce the cooling capacity of equipment, while intensifying droughts and extreme rainfall devastate fuel logistics and power plant infrastructure.
In contrast, emissions from fossil fuel power plants contribute to global warming, which in turn necessitates the adoption of increasingly costly technical adaptation measures to keep the units operational.
Strategic weight
The essential nature of thermal power plants lies in characteristics that sources such as solar and wind power are not yet able to fully provide, such as controllability and multifunctionality.
Currently, Brazil has 48 GW of installed capacity in thermal power plants, divided between 18 GW from renewable sources – where sugarcane bagasse dominates 70% of the segment – and 30 GW from non-renewable sources, led by natural gas.
This database provides the ONS (National System Operator) with the necessary flexibility to activate energy precisely during peak hours or when hydroelectric reservoirs are at critical levels.
This importance is even more vital for isolated systems, located mostly in the Northern Region. Approximately 2,6 million Brazilians depend almost exclusively on thermal power generation, with 68% of it fueled by diesel oil.
For these populations, the thermal power plant is not just a backup, but the only way to access electricity, which makes any operational failure an immediate social risk.
Logistical vulnerabilities
EPE's analysis identifies that climate threats are not merely theoretical, but are already affecting daily operations. In the Northern subsystem, the historic drought in the Amazon has reduced river levels, creating immense obstacles for the waterway transport of diesel and gas.
Without sufficient river depth, the supply logistics are compromised, increasing energy costs and threatening the continuity of service in remote areas. In the Southeast and Central-West subsystems, where bioelectricity production is concentrated, the risk is agricultural.
Extreme events such as heat waves and changes in rainfall patterns impact the sugarcane harvest. In recent years, these adverse conditions have reduced yield from bagasse by up to 11% compared to periods of stable weather.
Furthermore, managing conflicts over water use emerges as a critical issue, since the cooling of thermal power plants can compete with human water supply and irrigation during times of water scarcity.
Adaptation and resilience
To address this scenario, EPE points out that energy planning needs to incorporate climate stress scenarios into its long-term models, as has already been done in [previous projects/initiatives]. Ten-Year Energy Plan (PDE 2034) and in the National Energy Plan (PNE 2050).
Strengthening infrastructure involves investing in cooling technologies that require less water or use seawater, as well as promoting supply redundancy in isolated systems to avoid logistical blackouts. Another pillar of adaptation is fostering research in biotechnology to make biomass crops more resistant to extreme weather conditions.
EPE's conclusion is that the energy transition and system security cannot ignore thermal power plants, but must transform them into more resilient and efficient assets, ensuring that Brazil's "energy insurance" does not fail precisely at the time of the climate emergency.
Click here and check the fact sheets released by EPE.
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