As part of an initiative focused on modernizing and decarbonizing its electrical infrastructure, ISA Energía Brasil —a leader in the country's energy transmission sector— began installing Latin America's first 460 kV reactor that uses vegetable oil as an insulating and cooling fluid.
Supplied by Hitachi Energy, the 460 kV shunt reactor in this project uses a vegetable oil-based insulating fluid, increasing operational safety and reducing the environmental impact in high-voltage applications. The initiative, funded by ANEEL with an investment of approximately 18 million reais (around COP 13.74 billion), aims to replace traditional petroleum-derived mineral oil with a renewable organic compound. Located at the Bauru substation in the interior of São Paulo state, the equipment represents a technological milestone for the electricity sector, combining innovation, operational safety, and sustainability.
At an operational level, shunt reactors are essential for the safety of the electrical system: they absorb reactive power, which, when excessive, can cause a rise in grid voltages, especially in low-load situations or on long transmission lines. In this way, these large pieces of equipment contribute to grid stability, ensuring that energy reaches consumers safely, efficiently, and within the system's operating limits.
The project includes four single-phase shunt reactors with a capacity of 66.67 megavolt-amperes reactive (MVAr), and each unit requires approximately 14,700 liters of vegetable oil, for a total of roughly 58,800 liters of this sustainable input. The first unit will arrive at the substation in May, while the others are scheduled for August.
The Bauru substation is currently undergoing a modernization investment cycle (reinforcements and upgrades) totaling approximately 190 million reais (around COP 145 billion). This includes the installation of vegetable oil-insulated reactors and the replacement of other equipment and systems, which will increase operational reliability and enhance energy security for the National Interconnected System (SIN). In total, the Bauru substation project will also contribute to the creation of more than 100 direct and indirect jobs during construction. Furthermore, the substation will house the company's Oil Treatment Center, Special Maintenance Center, and Innovation Laboratory.
“Replacing the petroleum-derived input with a plant-based, renewable alternative reinforces ISA Energía Brasil’s commitment to initiatives that drive the clean energy transition and is fully in line with our 2040 Strategy. This unprecedented project demonstrates that it is possible to improve the electricity sector’s infrastructure by combining operational reliability and sustainability,” says Dayron Urrego, Executive Director of Projects at ISA Energía Brasil.
High-complexity engineering
The development of the reactor required a multidisciplinary team, involving both global and local Hitachi Energy teams, due to the complexity of using vegetable oil in a high-voltage environment, such as 460 kV. The higher the voltage level, the more complex the analysis of the equipment's internal insulating materials, demanding rigorous attention to detail at every stage of the engineering project.
This is a groundbreaking technology, designed from the ground up to run on vegetable oil. To make its manufacture feasible, Hitachi Energy conducted specific logistical studies, adapted existing processes, established partnerships with strategic suppliers, and deployed specialized equipment for handling the vegetable oil.
Sustainability and operational safety
The project represents a significant step towards the adoption of renewable insulating fluids in high-voltage applications, demonstrating the technical feasibility of creating an alternative to mineral oil, which is derived from fossil fuels. The use of a plant-based insulating fluid offers enhanced fire safety and significantly reduces the environmental impact of the operation.
Although vegetable oil fluids are denser than mineral oil, Hitachi Energy's advanced design and engineering capabilities have enabled the development of a reactor with an optimized design that reduces the unit's carbon footprint associated with material use by 20% and decreases total carbon emissions throughout the lifecycle by approximately 11%. This contribution supports ISA Energía Brasil's Net Zero commitments.
The environmental advantages are remarkable: vegetable oil is highly biodegradable, with over 99% biodegradation in approximately 10 days. Furthermore, life cycle analyses of the fluid indicate a lower carbon footprint compared to conventional fossil-based mineral oil, as the product absorbs CO₂ during its production process. Another advantage is the significant increase in substation safety: the fluid has a significantly higher flash point (combustion temperature) compared to mineral oil and holds FM Global international fire resistance certification.
The success of the operation could pave the way for the expansion of the use of this technology in other substations of ISA Energía Brasil, in line with its corporate strategy of combining operational efficiency with the decarbonization agenda, as well as constituting a benchmark for the national electricity sector.
Net Zero Commitment
In 2025, ISA Energía Brasil announced its roadmap to achieve net-zero emissions by 2050, reaffirming its commitment to climate change mitigation. The strategy combines mitigation and adaptation measures with clear objectives: to reduce its emissions by 60% by 2040 and achieve an absolute reduction of 90% by 2050 in its Scope 1, 2, and 3 emissions, using 2022 as a baseline. The remaining emissions will be offset, aligning the company with the Paris Agreement and the global goal of limiting warming to 1.5°C by 2100.
The company has made consistent progress on its climate management agenda. Key achievements include a 22% reduction in direct greenhouse gas emissions between 2022 and 2025, resulting from initiatives such as rigorous control of SF6 gas leaks, the implementation of self-generation of renewable energy through its own solar plants, and the reduction of fossil fuel use, among others. The company continuously invests in solutions that minimize environmental impact, such as the adoption of drones in the implementation and operation of its projects. On the Brazilian Stock Exchange, ISA Energía Brasil is included in the ICO2 (Carbon Efficiency), ISE (Corporate Sustainability), IDIVERSA (Diversity), IBRA, IBXX, IDIV, IEEX, IGCT, IGCX, MLCX, and UTIL indices.