In the heart of Brazil’s energy landscape, a groundbreaking study led by Pedro Ferreira Torres of the Instituto de Energia e Ambiente at the University of São Paulo is challenging conventional wisdom about how we manage and transmit electricity. The research, published in the journal Energies, explores the multifaceted benefits of Battery Energy Storage Systems (BESS) as more than just energy reservoirs—they are emerging as pivotal assets in transmission systems, particularly in regions with high renewable energy penetration.
Torres and his team focused on a 30 MW/60 MWh BESS installed in the city of Registro, São Paulo, primarily designed to alleviate congestion in the transmission grid. However, their findings reveal that this BESS can do much more. “The BESS not only enhances transmission capacity but also supports operational procedures during transients, helping maintain power quality requirements,” Torres explains. This means that during unexpected events or maintenance periods, the BESS can step in to keep the lights on and the grid stable.
The study identifies four key additional applications for the BESS: increasing operational flexibility under contingencies and maintenance, enabling islanded operation for increased reliability, supporting grid restoration during outages, and boosting the hosting capacity for variable renewables. These capabilities are crucial as Brazil’s power system faces a significant reduction in inertia due to the integration of more wind and solar power. The System Operator expects a 33% loss of inertia by 2030, making the flexibility provided by BESS even more critical.
One of the most compelling findings is the BESS’s ability to increase the penetration of photovoltaic (PV) generation. In simulations, the BESS helped accommodate excess generation at key substations, with the main limitation being the energy constraints of the BESS itself. This is a game-changer for regions aiming to maximize their renewable energy potential without overloading the grid.
Moreover, the BESS significantly reduced the percentage of unserved load during system restoration, making the process more flexible and efficient. “The BESS can make the restoration of loads in the region more flexible,” Torres notes, highlighting the system’s dynamic performance improvements.
The commercial implications of this research are vast. As the cost and energy density of BESS continue to decrease, these systems could become more cost-effective solutions for energy management. Projections from the National Renewable Energy Laboratory (NREL) estimate a 16–49% cost reduction by 2030 compared to 2022. This could lead to a paradigm shift in how transmission systems are planned and operated, potentially postponing additional investments in traditional transmission assets.
The study also underscores the need for a balanced approach in assessing the financial benefits of BESS as transmission assets. While direct comparisons between alternatives can be challenging, the multifaceted services provided by BESS make them a compelling option for future grid developments.
As Brazil and other countries around the world grapple with the integration of more renewable energy sources, the insights from this research could shape future developments in the field. By leveraging the full potential of BESS, energy providers can enhance grid stability, improve power quality, and support the transition to a more sustainable energy future. The study, published in Energies, offers a roadmap for how BESS can be integrated into transmission systems, paving the way for more resilient and flexible power grids.
