NTPC Vidyut Vyapar Nigam (NVVN) has invited bids to set up a 250 MW/500 MWh standalone battery energy storage system (BESS) in Kerala. The BESS installation will be at the 220 kV Brahmapuram substation in Kochi, Kerala with an interconnection at the 220 kV voltage level within the jurisdiction of Kerala State Electricity Board (KSEBL).

The project will be supported by viability gap funding at a rate of ₹1.8 million (~$20,286)/MWh, amounting to ₹900 million (~$10.14 million) for the total project capacity.

The project’s total storage capacity will be 500 MWh with a power rating of 250 MW, designed for a two-hour discharge duration.

Bids must be submitted by November 11, 2025. Bids will be opened on November 12.

Bidders must furnish an earnest money deposit of ₹480,000 (~$5,409.60)/MW, amounting to ₹1.2 billion (~$13.52 million), a document fee of ₹22,500 (~$253.58) including GST, and a processing fee of ₹1.35 million (~$15,224.50) plus 18% GST per total capacity quoted.

Successful bidders must submit a performance bank guarantee (PBG) of ₹1.2 million (~$13,524)/MW.

The contract period will be 16 years, during which the BESS developer will be responsible for the complete operation and maintenance, including safety and system performance.

The scope of work includes the design, engineering, supply, installation, testing, commissioning, and operation of the BESS. The developer must also construct an interconnection bay at the 220 kV state transmission utility substation, along with the required control, protection, metering, and cybersecurity systems.

The system must maintain a minimum round-trip efficiency of 85%, a minimum annual availability of 95%, and support a cycle life of at least one full charge-discharge cycle per day, equating to 400 cycles annually. The dispatchable capacity should not degrade below 70% by the end of the 16-year contract period.

The scheduled commissioning date is set at 18 months from the effective date of the battery energy storage purchase agreement, with a maximum permissible delay of six months, subject to liquidated damages.

Delays in commissioning will result in proportional PBG encashment, and round-trip efficiency below 70% will lead to forfeiture of tariff payments for that month. A failure to maintain 50% availability for two consecutive years will be treated as an event of default, resulting in the termination of the battery energy storage purchase agreement.

Selected bidders must pay liquidated damages if the annual system availability during charging cycles falls below 95%.

Bidders must have a minimum net worth of ₹4.8 million (~$54,096)/MW, which amounts to ₹2.4 million (~$27,048)/MWh as of the last financial year, translating to ₹12 billion (~$135.24 million) for the full 250 MW capacity. The annual turnover requirement is ₹16 million (~$180,320)/MW, amounting to ₹80 million (~$901,600)/MWh for the preceding financial year.

In September this year, NVVN issued a tender to develop a 1,000 kW grid-connected rooftop solar project at the Defense Research and Development Organization premises in Jodhpur, Rajasthan.

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