NTPC Green Energy Limited has issued an engineering, procurement, and construction (EPC) tender for a 250 MW/1,000 MWh battery energy storage system (BESS) at its Kayamkulam facility in Kerala. The project is split into two segments: Block-1 includes 125 MW/500 MWh connected to the existing 33 kV solar pooling switchgear, while Block-2 comprises 125 MW/500 MWh to be integrated with the 220 kV switchyard.

As per the tender guidelines, the scope includes complete design, engineering, packaging, transportation, unloading, construction, erection, testing, and commissioning of the BESS on a turnkey basis. This also covers provision of high-tension and low-tension systems, transformers, auxiliary power, monitoring and control systems, and remote monitoring infrastructure. Bidders may submit proposals for either or both blocks.

Additional responsibilities for bidders include conducting grid compliance studies, providing reactive power compensation, and ensuring power quality compliance up to the 400 kV/220 kV interconnection point at the NTPC switchyard.

The BESS must be supplied in standardised containers, each with a minimum direct current capacity of 5 MWh, and must adhere to National Fire Protection Association standards. Each container must be equipped with battery racks, battery and energy management systems, supervisory control and data acquisition, power conversion, protection, and communication systems.

The successful bidders will be required to operate and maintain the BESS for a period of 15 years. They must also construct a control room with switchgear space, all internal electrical fittings, furniture, and a security cabin.

The batteries and the entire BESS must be designed for a lifespan of 15 years from the date of successful trial run, assuming one complete charge-discharge cycle per day. The deadline for bid submission is 24 June 2025.