CEA Pushes Ester Oil Adoption In Transformers To Reduce Crude Oil Dependence And Improve Fire Safety

The Central Electricity Authority (CEA), operating under the Ministry of Power, Government of India, has issued a new advisory promoting the use of ester oil as an alternative insulating and cooling medium in transformers and reactors across the country’s power sector. The move is aimed at reducing dependence on mineral oil, which is currently the most commonly used insulating fluid in electrical equipment and is largely produced from imported crude oil.

According to the advisory, the CEA has asked all central, state, and private transmission utilities to ensure that at least 10% of all newly procured transformers and reactors of 33 kV and above use ester oil. The authority has further recommended that this target should ideally include an equal mix of natural ester oil and synthetic ester oil, with 5% allocation for each category.

The advisory has been issued in line with the Central Electricity Authority Regulations 2023, which require all electrical plants and equipment to maintain proper insulation levels, adequate ratings, and safety measures to protect human life, electrical systems, and property. Ester oil has been identified as a suitable technological option because of its high fire safety characteristics and environmentally friendly nature. Unlike conventional mineral oil, ester oil is biodegradable and is considered safer for use in densely populated and environmentally sensitive areas.

The CEA noted that several major Indian utilities have already adopted ester oil technology in selected projects. These include Gujarat Energy Transmission Corporation (GETCO), NTPC, Power Grid Corporation of India, and Indian Railways. Indian standards are available for both mineral oil and ester oil, allowing utilities to select the most suitable option based on technical requirements and operational experience.

The authority has also clarified that utilities must ensure technical compatibility before adopting ester oil technology. Transformer and reactor designs should be fully suitable for ester oil usage, and utilities are required to obtain recommendations or certifications from Original Equipment Manufacturers (OEMs). In addition, proper testing, filtration, maintenance, and monitoring facilities must be available before implementation.

The advisory further stated that ester oil can be adopted wherever technically feasible. However, in cases where statutory regulations specifically mandate dry-type transformers or any other technology, those provisions will continue to prevail.

The advisory was signed by Assistant Director Gaurav Srivastava and circulated to power sector undertakings, generation companies, transmission utilities, and distribution companies. The CEA emphasized that faster implementation of ester oil technology is important, especially amid the ongoing West Asia crisis, which continues to impact global crude oil supply and imports.