In a significant technological breakthrough, Power Grid Corporation of India Limited (POWERGRID) has officially commissioned the nation’s first 315 MVA, 400/220/33 kV synthetic ester oil-filled power transformer.
Unveiled at the Bhiwadi Sub-station in Rajasthan, the unit is the largest of its kind in India by both capacity and voltage class. By replacing traditional mineral oil with a biodegradable synthetic ester fluid, the Maharatna PSU is establishing a new benchmark for fire safety and environmental sustainability in the country’s high-voltage transmission network.
Features:
The transition to synthetic ester oil addresses critical operational risks. Unlike conventional insulating oils, this next-generation fluid features a significantly higher fire point of approximately 330°C, providing a robust safeguard against fire hazards in densely populated or industrial zones like the National Capital Region (NCR).
Manufactured by Hitachi Energy at its Maneja facility in Vadodara, the transformer also offers superior thermal performance and a longer operational lifespan. This domestic production aligns with the ‘Atmanirbhar Bharat’ initiative while ensuring that the Northern Grid can handle high load conditions with increased resilience.
Vision for a resilient grid:
The inauguration was led by Dr. R. K. Tyagi, Chairman and Managing Director, POWERGRID, in the presence of senior board members, including the Directors of Finance, Operations, and Projects. Dr. Tyagi noted that this installation is a core component of the corporation’s strategy to modernize India’s energy backbone.
“This project is not only a milestone in technological innovation but also a strong reaffirmation of POWERGRID’s commitment to India’s green energy mission and sustainable development goals. The new transformer aligns with the nation’s vision for cleaner, safer, and more resilient power infrastructure.”
As of late 2025, POWERGRID maintains a dominant presence in the sector, overseeing more than 181,894 circuit kilometers of transmission lines and 287 substations. With a transformation capacity exceeding 5.94 lakh MVA, the company has consistently achieved a system availability rate of over 99.84%.
The successful deployment of this ester-filled unit underscores POWERGRID’s leadership in adopting global best practices and digital automation to meet the growing industrial and urban power demands of the Northern Region.

