KPTCL to replace mineral oil with ester oil in high-capacity transformers across Karnataka

Karnataka Power Transmission Corporation Limited (KPTCL) intends to swap mineral oil for ester oil in high-capacity transformers throughout the State within the next year, despite the higher cost of the former. A KPTCL official explained that ester oil, derived from vegetables, functions as a coolant and possesses a high flash point, preventing transformer ignition.

Additionally, ester oil is biodegradable, non-toxic, and prolongs transformer life. The utility opted for this cost-effective strategy instead of replacing ageing transformers during rainy seasons, which would entail significant capital expenditure. While mineral oil currently costs ₹213 per litre, ester oil is priced at ₹275 per litre; however, the expense of repairing damaged transformers surpasses the cost of procuring ester oil.

KPTCL presently oversees 3,754 transformers in the State and has already replaced conventional mineral oil with ester oil in 45 high-capacity transformers, utilizing approximately 1,500 litres worth over ₹8 lakh in these units. The ester oil was initially employed in Harapanahalli substation near Davangere in 2017 on a pilot project basis, with positive outcomes reported.

The official disclosed that other states, including Gujarat, Maharashtra, and Mumbai's Tata Power, have also adopted ester oil in their power grids. Examples of stations where ester oil has been implemented in Karnataka include C.T. Kere, Dobspet, Rajajinagar, Pottery Road, Banashankari, Doddaballapur, and Bagepalli.