Tamil Nadu Green Energy Corporation Limited (TNGECL) has announced the results of its auction to set up standalone battery energy storage systems (BESS) aggregating 350 MW/1,400 MWh, against a tendered capacity of 375 MW/1,500 MWh floated in November 2025.
Eagle Construction has secured 175 MW/700 MWh at a tariff of Rs 315,000 per MW per month, while OPG Power has secured 175 MW/700 MWh at Rs 316,000 per MW per month. The projects will supply storage capacity to Tamil Nadu Power Distribution Corporation Limited (TNPDCL) for on-demand charging and discharging, with interconnection to the Tamil Nadu Transmission Corporation Limited (TANTRANSCO) or TNPDCL network. The systems will operate at a C-rate of 0.25 and must be capable of charging or discharging in blocks ranging from 25 MW/100 MWh to 50 MW/200 MWh up to the contracted capacity. Developers are required to provide 1.5 full operational cycles per day, ensure minimum annual system availability of 95 per cent and guarantee an AC-to-AC round-trip efficiency of at least 85 per cent up to the metering point on a monthly basis.