Capacitor electric vehicle

A capacitor electric vehicle is a vehicle that uses supercapacitors (also called ultracapacitors) to store electricity. the best ultracapacitors can only store about 5% of the energy that lithium-ion rechargeable batteries can, limiting them to a couple of miles per charge. This makes them ineffective as a general energy storage medium for passenger vehicles. But ultracapacitors can charge much faster than batteries, so in vehicles such as buses that have to stop frequently at known points where charging facilities can be provided, energy storage based exclusively on ultracapacitors becomes viable. China is experimenting with a new form of electric bus, known as Capabus, which runs without continuous overhead lines (is an autonomous vehicle) by using power stored in large onboard electric double-layer capacitors (EDLCs), which are quickly recharged whenever the vehicle stops at any bus stop (under so-called electric umbrellas), and fully charged in the terminus. A few prototypes were being tested in Shanghai in early 2005. In 2006 two commercial bus routes began to use electric double-layer capacitor buses; one of them is route 11 in Shanghai. In 2009 Sinautec Automobile Technologies, based in Arlington, Virginia, and its Chinese partner Shanghai Aowei Technology Development Company are testing, with 17 forty-one seat Ultracap Buses serving the Greater Shanghai area since 2006 without any major technical problems. During the Shanghai Expo in 2010, however, 40 supercapacitor buses were being used on a special Expo bus service and owing to the supercapacitors becoming overheated some of the buses broke down. Buses in the Shanghai pilot are made by Germantown, Tennessee-based Foton America Bus Company Another 60 buses will be delivered early next year with ultracapacitors that supply 10 watt-hours per kilogram. The buses have very predictable routes and need to stop regularly every or less, allowing quick recharging at charging stations at bus stops.