State-run NTPC has invited global expressions of interest to develop and install a grid-connected sodium-ion battery energy storage system (BESS), stepping up efforts to evaluate alternatives to lithium-ion batteries as India’s renewable energy capacity and storage requirements rise.
The pilot will be set up at existing NTPC thermal power stations or office buildings and will assess technical performance, safety, reliability, degradation, operating characteristics and techno-commercial viability under Indian grid and climatic conditions. The last date for submitting bids is October 15, 2026, with responses scheduled to open on October 16.
The move is significant as India remains heavily dependent on imported battery materials. NTPC said the country has “limited domestic availability of commercially exploitable lithium resources” and depends substantially on imports for battery cells and certain raw materials.
“Sodium-ion battery technology is emerging as one of the potential alternatives for stationary energy storage applications,” NTPC said. It added that sodium is abundantly available and the technology could reduce dependence on lithium and certain other critical materials, opening up possibilities for a more indigenous storage supply chain.
NTPC has sought proposals under two configurations. The first is a 100 kWh usable-energy-capacity pilot BESS, intended to provide a common basis for comparing technologies. Under the second option, applicants can propose a suitable capacity based on their technology, standard configuration and demonstration requirements.
For technologies at Technology Readiness Level (TRL) 4 and 5, applicants will have to contribute at least 50% of the total project cost. For TRL 6 and above, no minimum financial contribution is mandatory, while proposals below TRL 4 will not be considered.
The pilot will also be used to assess cost, scalability, indigenous manufacturing potential and long-term performance, and could help NTPC frame specifications for future demonstration or commercial projects.
NTPC Group currently has 91,080 MW of installed capacity, with more than 37 GW under construction. It is targeting 149 GW by 2032, including 60 GW of renewable energy capacity. In FY26, it generated 432 billion units, accounting for about 24% of India’s electricity generation.