Power Grid Corporation of India (POWERGRID) has invited bids to set up 375 MW/1,500 MWh standalone battery energy storage systems (BESS) in seven locations in Tamil Nadu.

The last date to submit bids is January 28, 2026. Bids will be opened on the same day.

Bidders must submit a tender fee of ₹25,000 (~$275).

Last year, the Tamil Nadu Green Energy Corporation had invited bids to set up seven standalone BESS with a total capacity of 375 MW/1,500 MWh.

POWERGRID intends to participate in the tender, and if it wins, the successful bidders will execute the project in association with POWERGRID.

Selected bidders must not participate in the tender directly or indirectly through their subsidiaries, partnerships, ownership, individual firms, or a consortium.

They will sign a memorandum of understanding with POWERGRID set up the standalone BESS projects.

The scope of work covers the comprehensive operation and maintenance of the projects for 15 months.

The projects must be completed within 15 months.

According to the TNGECL tender, the BESS must be designed for 1.5 full operational cycles per day.

The BESS must be designed to charge and discharge at a C rate of 0.25.

Additionally, the BESS must be capable of charging or discharging in groups ranging from 25 MW/100 MWh to 50 MW/200 MWh, up to the total rated capacity specified in the battery energy storage supply agreement.

The systems must guarantee a minimum annual system availability of 95% and an AC-to-AC round-trip efficiency of at least 85% at the metering point each month.

Tamil Nadu Power Distribution Corporation will provide the required power for charging the BESS, subject to the minimum system efficiency specified in the agreement.

The Tamil Nadu Transmission Corporation will provide land on a right-to-use basis at an annual lease fee of ₹1 (~$0.011)/project/year.

The projects will also receive viability gap funding (VGF) of ₹1.8 million (~$20,186)/MWh of the awarded capacity. The VGF will be disbursed in three tranches: 20% at financial closure, 50% at commercial operation date (COD), and 30% a year post-COD upon certification.
Only commercially established and operational technologies must be used to minimize technology risk and achieve timely commissioning of the projects.

Recently, POWERGRID floated two tenders to set up standalone BESS of 187.5 MW/750 MWh each at two of Transmission Corporation of Telangana’s Maheswaram and Choutuppal substations.