- Why in news
- On 24 October 2026, the Setting to Work Phase-2 activity of the DRDO-developed AIP Energy Module was inaugurated at L&T's Hazira complex in Gujarat. The module is meant for Kalvari-class submarines.
- What it is
- Air Independent Propulsion (AIP) lets a conventional diesel-electric submarine run submerged for longer without surfacing or snorkelling to charge batteries. The Indian system is a fuel-cell based energy module developed by the Naval Materials Research Laboratory (NMRL), DRDO. It is meant to be retrofitted into Kalvari-class submarines.
- Developer
- The AIP Energy Module was developed indigenously by the Naval Materials Research Laboratory (NMRL) of DRDO.
- What it does
- AIP raises the underwater endurance of diesel-electric submarines by cutting their dependence on atmospheric oxygen.
- Technology type
- The system uses hydrogen and fuel cells, which demand a strict safety culture.
- Next step
- The module will be energised and tested to Navy protocols, then handed to Mazagon Dock Shipbuilders Limited for integration on a Kalvari-class submarine in early 2027.
Don’t confuse with AIP vs nuclear propulsion: AIP extends the submerged time of a conventional submarine, though far less than a nuclear reactor does. Nuclear submarines (SSN/SSBN) need no air and are limited mainly by crew endurance.
Don’t confuse with NMRL vs DRDO: NMRL is one laboratory of DRDO, working on naval materials. DRDO is the parent R&D organisation under the Ministry of Defence.
Defence: Prelims tests exercises (with whom), equipment (who makes it) and firsts.
Why it matters
- Longer submerged endurance makes conventional submarines harder to detect, strengthening the Navy's underwater capability.
- An indigenous system supports self-reliance in defence technology (Atmanirbhar Bharat).
Problems
- Handling hydrogen and fuel cells safely inside a submarine hull is demanding.
- Integrating a new module into existing hulls needs long trials and must meet Navy induction timelines.
Way forward
- Complete rigorous energised testing to Navy protocols before integration.
- Extend the system to later submarine projects once proven.
Put in your answer
Indigenous AIP programme: NMRL-DRDO's AIP Energy Module, built with industry partners, is moving from design to shop-floor testing, an example of DRDO-industry cooperation.
No close past question yet.
No practice question for this one; the card may still help an answer. Why: Indigenous DRDO AIP module for submarines is a lasting defence-tech topic; defence hardware seldom reaches Mains and few Prelims facts here.
Worth revising until Prelims 2028: most news questions come within two years of the event.