Like cars, trains waste large amounts of energy during braking. Until now, however, there has been no practical way to recover this energy by using regenerative braking. Locomotives do not carry large batteries, and they are typically connected to an electrical grid that can’t handle quick bursts of energy.
Ultracapacitors, which offer extremely high charge/discharge rates and long cycle life, could provide a solution.
Ultracapacitor specialist Maxwell Technologies has announced that it is supplying its technology for a regenerative braking energy storage system used by the Beijing subway system.
The China Railway Rolling Stock Corporation will use Maxwell’s 48-volt modules in two sets of regenerative braking energy storage devices for the system’s No. 8 line, which runs through the heart of China’s capital.