In a first in the country, the Kolkata Metro will be installing a battery-based power system to provide critical back up in the event of grid failures.
Metro officials said that in the event of grid failures, the Metro trains will no longer remain stranded in tunnels as the “cutting-edge” Battery Energy Storage System (BESS) can propel stranded coaches at 30 km/h to the nearest station.
“This innovative technology will significantly enhance passenger safety and improve energy consumption, marking a first-of-its-kind initiative for Indian Railways and all Metro systems across the country,” the Kolkata Metro said in a statement.
The BESS is a combination of inverters and Advanced Chemistry Cell (ACC) batteries. It will be installed at the Central sub-station of the Blue Line.
“Funded under the National Programme on Advanced Chemistry Cell Battery Storage, this project underscores Kolkata Metro’s commitment to eco-friendly and safe operations. The project has garnered interest from global giants like Siemens, Toshiba, Delta, and Eaton. Following a competitive bidding process, Delta Electronics Pvt. Ltd. was awarded the contract to install the 4 MW BESS, featuring 6.4 MWh Lithium Iron Phosphate (LFP) batteries,” the Metro added.
According to the Kolkata Metro, the LFP battery pack successfully passed inspection in Taiwan in early February this year by a team authorised by the Railway Board. “Dispatch clearance has been issued, and the battery pack is expected to arrive at the installation site by mid-March. Commissioning and full operation are anticipated by May this year,” the Metro said.
“Adhering to the ‘Make in India’ policy, the power converter system will be manufactured in India by Delta Electronics’ Indian subsidiary, while the LFP batteries will be produced in Taiwan by the parent company.This groundbreaking system is designed to provide critical backup power in the event of power cuts or grid failures,” the Metro stated.
The BESS is projected to save Kolkata Metro approximately Rs 7 crore in peak hour demand charges and Rs 6 crore through power factor improvement over its 14-year lifespan.
The system also allows for energy storage during off-peak hours for use during peak times and maintains a power factor above 0.9, further enhancing savings. In emergencies, the BESS will provide backup power for essential systems like tunnel ventilation and platform ventilation.
Kolkata Metro plans to expand its BESS infrastructure by adding seven 1 MW units with Traction Energy Storage System (TESS) capabilities in new Blue Line sub-stations. “This expansion will enable the storage of energy generated during regenerative braking by the trains,” a Metro official said.