The Solar Energy Corporation of India Limited (SECI) has opened a new procurement round for 800 MW/3,200 MWh of standalone battery energy storage systems (BESS) that can supply electricity on demand. The SECI-ESS-IV tender is structured under tariff-based competitive bidding and will allow storage projects to be developed across India.
The tender represents a four-hour storage configuration, with 800 MW of power capacity matched by 3,200 MWh of energy capacity. SECI has set a minimum bid size of 50 MW/200 MWh, while a single bidder can bid for up to the full 800 MW/3,200 MWh capacity. The projects will be developed under a Build, Own and Operate model, placing project development and operating responsibilities with the selected BESS developers.
One of the notable requirements is the way the storage capacity will be used. The buying entities can call upon the BESS on an on-demand basis, with the discharge window structured around evening and night-time requirements. The available tender details indicate that discharge can be scheduled for any four hours beginning from 5 p.m. and ending by 11 a.m. the following day, while no discharge is scheduled between 11 a.m. and 5 p.m. The required discharge hours are communicated to the developer a day in advance.
The charging requirement also gives the tender a renewable-energy linkage. Developers must arrange the electricity used to charge the BESS, with at least 51% of the charging energy required to come from renewable sources. This creates a direct connection between standalone storage and renewable electricity rather than treating the batteries solely as conventional grid assets.
The developer's scope extends well beyond supplying battery equipment. Selected BESS developers will be responsible for identifying land, installing and owning the projects, obtaining grid connectivity and statutory approvals, and establishing the required interconnection. They will also bear applicable transmission-related costs up to the interconnection point and remain responsible for operation, maintenance and equipment and personnel safety.
The tender is technology-agnostic, allowing developers to select the BESS technology suited to their projects while meeting the specified performance and grid requirements. Projects can use applicable transmission or state network connectivity, with ISTS-connected projects requiring a minimum voltage level of 220 kV according to the tender details reported from the RfS.
Reliability is also built into the procurement structure. Developers must maintain minimum monthly system availability of 85%. Failure to meet the availability requirement can result in liquidated damages linked to the contracted discharge tariff and the unavailable energy. This shifts part of the commercial focus from simply installing storage capacity to maintaining dependable availability when the buying entity needs the stored power.
The financial qualification requirements are significant for developers entering the tender. The EMD is ₹7.184 lakh per MW of quoted capacity, while the reported performance bank guarantee requirement is ₹17.96 lakh per MW. The tender also specifies a ₹59,000 document cost and a bid processing fee of ₹20,000 per MW, subject to the prescribed maximum.
Online bids must be submitted by October 30, 2026, with the offline submission deadline on November 3. The bids are scheduled to open on November 4, following a pre-bid meeting on October 7. SECI will use an online bidding process followed by an electronic reverse auction for the procurement.
The tender comes as India's storage market moves toward longer-duration systems designed to shift electricity into periods of higher demand. SECI has already used storage-linked procurement to support renewable integration, while recent tenders have increasingly moved from two-hour configurations toward four-hour storage. The latest 800 MW round therefore adds another large procurement opportunity for standalone BESS developers while creating a mechanism for stored renewable electricity to be dispatched when required.
For developers, the key opportunity is not limited to the 3,200 MWh capacity being procured. The structure places land, connectivity, approvals, charging arrangements and long-term operational performance within the developer's scope, making execution capability as important as battery technology. For India's power system, the tender could add flexible storage capacity that helps shift renewable electricity toward periods when the grid needs it most.