NTPC Renewable Energy (NREL) has issued an engineering, procurement, and construction (EPC) tender for a grid-connected 250 MW/1,000 MWh battery energy storage system (BESS) at its Bikaner Solar project in Rajasthan.

Bids must be submitted by March 11, 2026. Bids will be opened on the same day.

Bidders must furnish an earnest money deposit (EMD) of ₹200 million (~$2.21 million).

The project involves setting up a BESS designed for single-cycle, four-hour discharge. The minimum installed capacity of the battery system must be 1,100 MWh, providing additional margin to meet performance and degradation requirements over the project life.

The BESS will be connected to the existing 33 kV system at the plant, with compliance requirements for reactive power support up to the 220 kV and 400 kV interstate transmission system (ISTS).

The injection point will be at the ISTS substation, and the termination point for the contractor’s scope will be at the owner’s 33 kV pooling switchgear

The scope of work includes design and engineering, supply of all major and auxiliary equipment, installation, testing, and commissioning of the BESS, and full integration with both the solar plant and the grid.

The project also covers energy management systems, battery management systems, power conversion systems, fire detection and suppression systems, auxiliary systems, and all associated balance-of-plant works.

In addition to EPC responsibilities, the selected bidder must provide comprehensive operation and maintenance (O&M) services for 15 years.

The BESS must be designed for a 25-year life, with batteries capable of at least 10,000 charge–discharge cycles. Over the 15-year O&M period, the system must maintain at least 92% of the guaranteed dispatchable capacity

Bidders must have experience in any one of the following:

Battery manufacturing and supply experience, requiring a cumulative supply of at least 80 MWh of batteries for grid-interactive BESS projects, including at least one single order of 20 MWh that has been operational for at least six months.

They must have experience in installing and commissioning a cumulative 80 MWh, again with at least one 20 MWh project operational for six months.

Bidders must have experience in EPC of grid-connected solar photovoltaic or wind power projects, requiring a cumulative installed capacity of at least 40 MWAC, including one plant of 10 MWAC or more that has been operational for at least six months.

The average annual turnover of the bidders over the last three financial years must be ₹1.53 billion (~$16.92 million).

The tender specifies penalties if the system does not meet a 98% availability and a minimum 80% round-trip efficiency.

Recently, NREL issued a tender for the supply of bifacial crystalline solar modules with a minimum rating of 570 Wp for a 400 MW solar project in Chitrakoot, Uttar Pradesh.

Earlier this year, NREL invited bids for the engineering, procurement, and construction of a 250 MW solar project with a 50 MW/200 MWh battery energy storage system in Sitapur, Uttar Pradesh.