NTPC Invites EOI for Pilot Grid-Connected Sodium-Ion Battery Energy Storage System

NTPC Ltd. has invited a Global Invitation of Expression of Interest (EOI) from technology providers for setting up a pilot grid-connected Battery Energy Storage System (BESS) based on Sodium-Ion Battery Technology at its existing thermal power stations and office buildings.

The EOI seeks participation from companies and technology providers capable of designing, supplying, installing and commissioning sodium-ion battery-based energy storage systems for demonstration purposes.

Under the EOI, NTPC has proposed two capacity options for the pilot project. Under Option 1, the BESS will have a usable energy capacity of 100 kWh at the Point of Interconnection (POI), which will serve as the common basis for evaluation. Under Option 2, applicants can propose their own capacity based on their standard configuration and a suitable scale for technology demonstration.

The pilot is intended to demonstrate sodium-ion battery technology in a grid-connected application. Applicants are required to indicate the Technology Readiness Level (TRL) of their proposed technology. Technologies below TRL 4 will not be considered.

For technologies at TRL 4 or TRL 5, the applicant will be required to contribute a minimum of 50 percent of the total project cost. For technologies at TRL 6 and above, there will be no mandatory minimum contribution, although the contribution will be mutually agreed between NTPC and the applicant. NTPC has stated that preference may be given to applicants offering a higher financial contribution.

In the case of TRL 4–5 technologies, NTPC may return the applicant's contribution after successful completion of the demonstration, subject to mutually agreed terms and conditions.

NTPC will evaluate the proposals on techno-commercial feasibility and may decide whether to proceed with installation of the pilot system. The company may implement the pilot either through nomination or by inviting a Request for Proposal (RFP) among shortlisted applicants.

As part of its scope, NTPC will provide land and site support for the pilot installation. It will also provide a 415 V LT feeder for charging and discharging of the BESS and auxiliary power, if required. NTPC will facilitate necessary approvals and support installation activities, operation and maintenance, and data analysis associated with the demonstration.

The selected applicant will be responsible for the complete design, engineering, manufacture, supply, transportation, storage, erection, testing and commissioning of the sodium-ion BESS. The scope will cover cells, modules and racks, Battery Management System (BMS), Power Conversion System (PCS), Energy Management System (EMS), switchgears, AC distribution boards and other auxiliary systems.

The applicant will also have to undertake electrical, control, communication, protection and metering integration with the existing system. Safety and fire protection systems will form part of the applicant's scope, along with necessary approvals and statutory requirements.

The selected technology provider will be required to provide a three-year comprehensive Annual Maintenance Contract (AMC), conduct performance demonstrations, supply necessary spares and consumables, and provide training to NTPC personnel. Applicants will also have to comply with applicable Make in India and public procurement requirements.

The EOI requires applicants to submit detailed technical information on their sodium-ion technology, including battery chemistry, cell parameters, configuration, system efficiency, depth of discharge, cycle life, calendar and design life, degradation characteristics, operating temperature range and charge and discharge C-rates.

Details regarding safety testing, thermal management, scalability, recyclability and reference plants are also required. Applicants must provide proposed pilot specifications, grid interconnection details, auxiliary consumption, land or space requirements, warranty provisions and terminal points.

The submission will also have to include the project's estimated cost and a detailed cost breakup covering the battery system, PCS, LT switchgear and ACDBs, EMS, control, monitoring and communication systems, auxiliary systems, civil and infrastructure works, installation and commissioning, balance of plant, safety and protection systems and miscellaneous costs.

Applicants are required to separately indicate the cost of the three-year AMC, project execution timeline, and the Indian and imported content of the proposed system. Details of domestic manufacturing capabilities and the proposed mode of project execution will also have to be provided.

On intellectual property rights, the technology provider will retain the intellectual property related to its sodium-ion battery technology. However, intellectual property generated specifically through a successful pilot demonstration will be jointly owned by NTPC and the applicant, with special provisions for commercialization in the case of TRL 4–5 technologies.

The last date for submission of responses is October 15, 2026, while queries and requests for clarification can be submitted up to October 5, 2026. Responses will be opened on October 16, 2026. The submitted responses will remain valid for six months from the last date of submission.