The Calcutta Electric Supply Corporation (CESC) has issued a request for selection (RfS) to set up a 40 MW/80 MWh standalone battery energy storage system (BESS) in Kolkata, West Bengal, under the build, own, operate, and transfer model.

Bids must be submitted by September 18, 2025.

Bidders must furnish an earnest money deposit of ₹60 million (~$684,579), a document fee of ₹29,500 (~$336.58) plus GST, and a document processing fee of ₹500,000 (~$5,704.82) plus 18% GST.

Selected bidders must pay a performance bank guarantee of ₹150 million (~$1.71 million).

The BESS must have two cycles daily for at least 12 years, which is also its mandated service life. It must also have a round-trip efficiency of 90%. It must have a system availability of over 95%.

Only commercially established and operational BESS technology must be used for the project.

The scope of work entails the site survey, planning, design, engineering, transportation, unloading, handling, supply, storage, installation, integration, testing, and commissioning of the BESS. It also involves conducting the project’s site area grading, civil works, integration, and demonstration for acceptance.

Successful bidders will be responsible for the BESS, from its design up to its 33 kV feeders’ connection up to CESC’s 33 kV switchboard at the New Cossipore Substation. The 33 kV switchboards must be installed in a switch-cum-control room/control centre to be constructed within the BESS area.

The scope of work also includes operating and maintaining the system. Additionally, it involves making the project available to CESC for charging/discharging on an ‘on-demand’ basis.

If the bay control and protection unit panels are not considered, selected bidders can install a separate relay, control, indication, and protection panel. They must also arrange the necessary auxiliary and backup power supply through a suitably sized station battery and charger system at an appropriate voltage level, as well as an uninterruptible power supply system to ensure uninterrupted operation of metering, protection, control, and communication equipment.

Successful bidders must provide a suitable optical fibre cable-based communication system compatible with CESC’s communication system. They must install an energy management system monitoring terminal to be placed at the switch-cum-control room remotely (through the cloud) for remote monitoring and controlling.

Selected bidders must install dedicated current transformers at the 33 kV intermediate bus. They must also implement a suitable metering arrangement to monitor the power flow in terms of applicable Central Electricity Authority metering regulations.

Bidders must have a minimum net worth of ₹600 million (₹6.84 million) at the end of the previous financial year or seven days before the bid submission deadline.

Bidders must have a minimum turnover of ₹2 billion (~$22.81 million) during the last financial year or seven days before the bid submission deadline. They must have a profit after tax plus depreciation of at least ₹100 million (~$1.14 million) at the end of the preceding financial year or seven days before the bid submission deadline.

Recently, the Maharashtra State Electricity Distribution Company issued a tender to procure 2,000 MW/4,000 MWh of BESS under the build, own, and operate model.