Silent shift

Hydrogen buses are pushing India's ambitious clean transport future

- BY BADAR BASHIR

IN THE HIGH-ALTITUDE cold desert of Leh, five green buses glide silently past Buddhist monasteries. Each costing ₹2.5 crore—nearly three times the price of a luxury diesel bus—they represent India’s hydrogen ambition. After field trials confirmed that their fuel cells could withstand subzero conditions, NTPC handed over the fleet to the Ladakh administration in mid-2025 for commercial use. Fuel cells generate electricity by combining hydrogen with oxygen from the air. At high altitudes, however, oxygen levels are significantly lower, which can affect performance.

In Ladakh’s oxygen-deprived environment, this can reduce efficiency and power output. Yet, this small hydrogen ecosystem, operating at 3,650 metres above sea level—the world’s highest-altitude hydrogen mobility project—appears to be functioning smoothly. To compensate for the lower oxygen concentration, the buses use high-performance air compressors to “force-feed” air into the fuel cell stack. The buses are equipped with specialised heating systems that pre-warm the stack. The system is designed to blow out any remaining water vapour from the exhaust and internal lines, preventing ice from forming inside.

In Ladakh, infrastructure had to be created from scratch. A 1.7 MW solar plant supplies renewable energy for electrolysis—the process of splitting water (H₂O) into hydrogen and oxygen. A green hydrogen filling station in Leh, with a capacity of 80kg per day, enables local refuelling. In dense urban centres such as Delhi, however, the required ecosystem would need to be far larger and more reliable.