The best ultracapacitors can only store about 5 percent of the energy that lithium-ion batteries hold, limiting them to a couple of miles per charge. But what ultracapacitors lack in range they make up in their ability to rapidly charge and discharge. So in vehicles that have to stop frequently and predictably as part of normal operation, energy storage based exclusively on ultracapacitors begins to make sense.
17 forty-one seat municipal buses demonstrate how effective using capacitors can be on the outskirts of Shanghai. Some bus stops along the route are charge stations. Sinautec’s ultracapacitor buses take big sips of electricity every two or three miles at designated charging stations, which double as bus stops. When at these stations, a collector on the top of the bus rises a few feet and touches an overhead charging line. Within a couple of minutes, the ultracapacitor banks stored under the bus seats are fully charged.
