New Delhi: India could witness significant expansion in sodium‑ion battery manufacturing within the next few years as researchers have advanced the technology to Technology Readiness Level (TRL) 7, Union Renewable Energy Secretary Santosh Kumar Sarangi said on Friday. He indicated that once a technology reaches TRL‑7 — where a system prototype has been demonstrated in an operational environment — moving from pilot projects to commercial production typically takes around two to three years.
What TRL‑7 means for sodium‑ion batteries
TRL is a standard scale used to assess how mature a technology is. TRL‑7 denotes demonstration of an integrated prototype in an operational setting, a step beyond laboratory validation and pilot cells. Reaching this milestone suggests developers have addressed many practical engineering and safety issues, making scale‑up commercially feasible.
Sarangi’s comments, made on the sidelines of the BloombergNEF Summit, framed sodium‑ion as one of several alternative battery chemistries that could strengthen India’s energy storage ecosystem as the share of renewables grows.
"A lot of research is going on in this area. In sodium‑ion batteries, there are researchers who have reached a TRL of 7 and above. Once you reach that stage, moving from a pilot to commercial production should take anywhere between two to three years. So, we should expect significant growth there," Sarangi said.
Where sodium‑ion fits in the market
Sodium‑ion batteries use sodium ions — a more abundant and cheaper element than lithium — to store and release energy. For India, where raw material security, cost and large‑scale deployment matter, sodium‑ion offers potential advantages:
- Lower raw material cost: Sodium is widely available and not subject to the same supply constraints as lithium.
- Supply chain resilience: Greater domestic sourcing potential could reduce import dependence.
- Suitable for stationary storage: Early use cases are likely to be grid and utility‑scale storage where energy density is less critical than cycle life and cost.
However, the technology is not without limitations. Sodium‑ion cells currently offer lower energy density than advanced lithium‑ion chemistries, making them less attractive for passenger EVs where range and weight are critical. Commercial competitiveness will depend on manufacturing scale, lifecycle costs and performance under Indian operating conditions — factors that only large‑scale deployment can validate.
Government expectations and other chemistries
Sarangi said the Central Electricity Authority (CEA) estimates India will need about 411 GWh of energy storage by 2031‑32, and the country is on track to meet or possibly reach that target earlier. He added that current installed storage is much lower but multiple tenders and orders indicate capacity under development.
| Item | Figure / Comment |
|---|---|
| Energy storage requirement (CEA estimate) | 411 GWh by 2031‑32 |
| Commercialisation timeline (sodium‑ion) | Approximately 2–3 years from TRL‑7 to commercial production, per Sarangi |
The Secretary also highlighted interest in other storage technologies such as vanadium flow batteries. He noted that domestic manufacturers are scaling supply and cited an order placed by NTPC Green Energy Limited for 100 megawatts of vanadium flow capacity. Sarangi said rising demand and higher volumes could help reduce costs for flow batteries, calling them a possible “game changer” if prices fall.
Implications for Indian users and manufacturers
For utilities and grid operators, diverse storage options help manage variability in solar and wind generation and support round‑the‑clock reliability. For domestic manufacturers, TRL‑7 progress signals an opportunity to invest in new lines and supply chains centred on sodium chemistries.
- Pros: Potential cost reduction, lower import dependence, suitability for large stationary storage projects.
- Cons: Lower energy density compared with leading lithium‑ion batteries, need for scale to verify long‑term performance, requirement for manufacturing expertise and capital.
Sarangi’s remarks suggest policymakers will continue to back a technology‑agnostic push for storage, while private and public developers race to prove economics at scale. If sodium‑ion and flow batteries scale as expected, India could accelerate its transition to a renewable‑dominated grid with storage tailored to domestic needs and resources.
Reporting based on statements by the Union Renewable Energy Secretary and data cited from the Central Electricity Authority and NTPC Green Energy Limited.
