ISA Energia Brasil inaugurated the Riacho Grande project, implementing Brazil’s longest underground transmission line with 44.6 km, connecting São Paulo to the ABC Paulista region. The project, delivered five months ahead of schedule, enhances energy reliability and security for over two million residents in a high-demand urban area, signaling increased grid resilience and capacity expansion to accommodate future industrial growth.
The Riacho Grande transmission line represents an investment of R$ 1.1 billion and features a 44.6 km underground cable system augmented by an additional 9 km of overhead lines. The infrastructure connects the metropolitan São Paulo area to the ABC region, facilitating the transmission of Itaipu hydroelectric plant energy towards a region with continuous industrial expansion and dense electricity consumption. The project includes the newly built São Caetano do Sul Substation, covering 11,800 square meters with an installed capacity of 800 MVA. Equipped with Gas-Insulated Switchgear (GIS) technology, the substation reduces spatial footprint by up to 75%, a critical factor for urban deployment. Three identical transformers, each rated at 400 MVA and designed for silent operation under full load, provide operational flexibility; two run constantly while the third serves as an emergency reserve.
ISA Energia Brasil has incorporated real-time monitoring technology within the underground cables to detect operational variations, allowing for improved preventive maintenance and enhancing network reliability. The construction process prioritized minimizing urban disruption, employing technologies such as drone-assisted installation and strategic elevation of transmission cables. A 120-meter, 100-ton tower near São Paulo’s Billings Reservoir was erected as part of the overhead infrastructure, exemplifying engineering challenges faced in dense urban environments.
Sector authorities from the National System Operator (ONS) and the Ministry of Mines and Energy (MME) attended the launch, emphasizing the project’s role in bolstering the national interconnected system’s operational robustness, mitigating risks, and providing resilience against extreme weather events. The early completion underscores ISA Energia Brasil’s leadership in advancing Brazil’s energy transmission capacity and urban infrastructure, critical to supporting the growing energy demand of the São Paulo metropolitan area and fostering sustainable industrial development.
