TOSA stands for Trolleybus Optimisation Système Alimentation. It is billed as a zero-carbon-emission solution as the electricity used comes entirely from clean hydro power, at least in Geneva. ABB says the charging time is so quick that it does not interfere with the bus schedule and does not need overhead lines while providing greater route flexibility. The system uses a laser-controlled moving arm, which connects to an overhead receptacle for charging at bus shelters, instead of the usual trolley poles to overhead lines.