Tamil Nadu Green Energy Corporation has invited bids for setting up 500 MW/1,000 MWh standalone battery energy storage systems (BESS) in six locations on a build-own-operate model in Tamil Nadu.

Bids must be submitted by April 2, 2025. Bids will be opened on April 3.

Bidders must submit an earnest money deposit of ₹200,000 (~$2,303.78)/MW and a performance bank guarantee of 40% of the annual payment to the developer.

They must also submit a bid processing fee of ₹1.5 million (~$17,278.4) plus 18% GST.

The scope of work entails setting up the BESS projects is six locations to allow Tamil Nadu Generation and Distribution Corporation (TNPDCL) to charge/discharge BESS on demand. The project must also enable charging and discharging in groups from 50 MW/100 MWh and 100 MW/200 MWh.

The BESS projects must be designed for interconnection with the state transmission utility network. It must also be designed to charge and discharge with a C-rate of 0.5.

Selected bidders must make the BESS available for two full operation cycles daily and guarantee a minimum system availability of 95% annually.  They must also ensure 100% of the minimum dispatchable capacity of the BESS project.

They must guarantee a minimum AC-to-AC round-trip efficiency of 85% for the BESS every month.

Successful bidders must only promote commercially established and operational technologies to minimize the technology risk and achieve timely project commissioning.

The project must be completed within 18 months of the award.

The BESS will be charged by drawing power from the TNPDCL and injecting power into the TNPDCL network per dispatch instructions issued by state load dispatch centers. TNPDCL will provide the required power for charging the BESS per the minimum system efficiency agreement.

The Tamil Nadu Transmission Corporation will provide land to the selected bidder for an annual lease rate of ₹1 (~$0.011)/project/year.

The Ministry of Power has allocated viability gap funding (VGF) to develop BESS projects for states with more than 3 GW intra-state solar power projects, earmarking 1,000 MWh for Tamil Nadu.

The Central government will provide VGF of 30% of the BESS’ capital cost or ₹2.7 million (~$31,101)/MWh, whichever is lower. The VGF will be disbursed in five tranches.

Bidders must apply for at least 100MWh (50 MWX 2 hours). A single bidder will be awarded up to 50% of the total bid capacity. Bidders must quote a tariff of less than ₹250,000 (~$2,879.72)/MW/month.

The BESS project is technology agnostic.

Bidders must have a minimum annual turnover of ₹5 million (~$57,594.5)/MW in the last three financial years.

Recently, SJVN requested a selection to develop a 375 MW/1,500 MWh standalone BESS in Uttar Pradesh under the build-own-operate model. The project has VGF support from the central government.

A month ago, Telangana Power Generation Corporation invited bids to set up a pilot project of 250 MW/500 MWh standalone BESS in Telangana.