The Tango LRV, one of 32 such vehicles in the TPG fleet, stores energy from the regenerative braking system in a roof-mounted module for reuse as traction power during acceleration.

During the first tests on July 6, the vehicle covered a distance of 1500m operating at low speed on a TPG depot circuit with the pantograph lowered. The supercapacitor unit weighs around a tonne and can store the equivalent of the entire kinetic energy of the vehicle travelling at 55km/h. Stadler says supercapacitors have a major advantage over batteries because they can absorb and release the very high levels of current generated during braking.

The prototype vehicle is being extensively tested by TPG and Stadler in conjunction with ABB, which supplied the traction converters. If the trials are successful, the system could be fitted to other Tangos in the TPG fleet.