Every time a bus, police car or mini sightseeing cart go by, you hear it: the soft buzz of an electric motor pushing wheels on pavement. Almost every official vehicle for the Expo is electric, whether it's powered by fuel cells, batteries or supercapacitors.
Shanghai already employs supercapacitor buses in its regular Metro system. Supercapacitors have the advantage of incredibly fast charging compared to a standard lithium-ion battery, which allows Shanghai's super-cap buses to quickly top off every time they coast into a stop. A special electrical connector extends from the roof, making contact with an awning to recharge. It takes about 30 seconds, ideal for a vehicle making frequent and regular stops. Sunwin, the maker of the buses, is a partner of Volvo in China--more info on the super-cap buses can be found here.
Also on hand are more traditional electric buses running on Li-ion batteries. To keep constant service, the batteries can be swapped when empty and recharged overnight, keeping stocks fresh.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.