Metro Railway, Kolkata, has saved over INR 8 crore in energy costs in 2024-25 by adopting regenerative braking systems across its fleet, officials said on Saturday.
According to Metro authorities, the technology, which enables electric motors to function as generators during braking, has helped regenerate around 1.08 crore units of electricity and reduce carbon emissions by 13,500 tonnes in the last financial year.
Currently, 37 rakes with this system are in operation.
The system allows the kinetic energy produced during braking to be converted back into electricity. This power is either fed back into the third rail for use by other trains or stored in batteries, and is also used to illuminate coaches and operate air-conditioning systems.
Besides rakes, regenerative braking is also being used in newly installed Metro lifts. These lifts, which do not require machine rooms, use significantly less power, Metro officials said.
In older NGEF rakes, energy generated during braking would be dissipated as heat through resistance. The modern rakes now come equipped with in-built regenerative braking technology, enabling an estimated 17–20 per cent of energy recovery during operations, according to a study by Metro Railway.
Metro Railway is also in the process of setting up a 4 MW Advanced Chemical Cell (ACC) Battery Energy Storage System, billed as the first of its kind in Indian Railways.
The system is expected to be operational by mid-July. A separate 7 MW Traction Energy Storage System has also been sanctioned by the Railway Board.
Officials said the adoption of these technologies is part of Indian Railways' larger goal to become a net-zero carbon emitter by 2030.