The Calcutta Electric Supply Corporation (CESC) has issued a request for selection (RfS) to establish West Bengal's first standalone battery energy storage system (BESS) with a capacity of 40MW/80MWh.

The project represents a significant leap as West Bengal steps into the battery storage space. The battery energy storage system will be located at the New Cossipore Generating Station. Bids must be submitted before September 18, 2025.

Project Structure and Technical Specifications

The project will operate under a BOOT (Build-Own-Operate-Transfer) model, with CESC providing the land and handling both charging and power offtake. The power purchase agreement will span 12 years. Storage units must connect at a minimum voltage level of 33 kV.

The comprehensive scope of work encompasses site survey, planning, design, engineering, transportation, unloading, handling, supply, storage, installation, integration, testing, and commissioning of the Battery Energy Storage System. Additionally, the project includes grading the project site, executing civil works, and demonstrating integration for project acceptance.

Performance Requirements and Operational Standards

The battery system is expected to operate up to two full charge-discharge cycles daily. These cycles can be either two-hour cycles or broken into multiple shorter sessions. To ensure consistent performance, the operator must maintain 95% monthly availability.

Failure to maintain this availability standard would result in penalties equal to double the agreed tariff. Efficiency requirements are set at 90% monthly, with financial repercussions for performance dipping below 70%.

The project allows for an annual degradation of 2.5%. However, failure to meet the minimum dispatchable capacity will result in commercial deductions calculated based on the average DAM peak market-clearing price.

Timeline and Financial Requirements

The project must be commissioned within 18 months, with a 6-month extension allowed. Delays beyond the original deadline would incur penalties. Financial closure is required within 9 months of signing the Battery Energy Storage Purchase Agreement (BESPA). Bidders must quote an all-inclusive price in INR per MW per month. 

If the BESPA is not signed within 12 months of the bid award, the agreement can be canceled by mutual consent. The bidders are required to have a minimum net worth of 600 million at the end of the previous financial year or seven days before the bid submission deadline.