The DRDO has moved to the second phase of developing an indigenous Air-Independent Propulsion (AIP) system for submarines. The technology aims to significantly extend the underwater endurance of the Indian Navy’s Kalvari-class fleet, with integration planned for 2027.
The Defence Research and Development Organisation (DRDO) has launched the next stage in developing an indigenous Air-Independent Propulsion (AIP) system. This technology is designed to solve a critical limitation for diesel-electric submarines: the need to frequently surface to draw air, which increases the risk of detection. By using hydrogen-based fuel cell technology, the AIP system allows submarines to remain submerged for much longer periods, greatly enhancing stealth capabilities.
The development process is currently at the testing phase for the system’s energy module. Larsen & Toubro (L&T) is handling the trial protocols at its Hazira facility in Gujarat, moving the technology from laboratory design to industrial-scale manufacturing. Once these power production tests are successful, the responsibility for installation will shift to Mazagon Dock Shipbuilders Limited, which will integrate the module into the Indian Navy’s Kalvari-class submarines. The government has set a target for this integration to be completed by 2027.
For investors monitoring the defense sector, the transition to local manufacturing involves both potential and risk. On the positive side, the successful implementation of this technology supports the country's push for self-reliance in high-end defense hardware, reducing dependence on foreign suppliers for critical submarine components. This can lead to long-term cost benefits and more secure supply chains for the Navy.
However, the project comes with technical and execution challenges. Retrofitting complex, hydrogen-based fuel cell technology into existing submarine hulls is an intricate engineering task that requires stringent safety standards. In the defense sector, large-scale projects often face risks related to timeline delays, cost increases during the production phase, and the difficulty of scaling experimental technology to real-world operational environments. Investors generally monitor such projects for updates on milestone completion and evidence that the technology is meeting the required performance benchmarks. The next key updates to track will be the progress of power trials at the Hazira facility and any official timelines regarding the start of integration at the shipyard.