The cities of Graz, Austria (pop. 280.000) and Sofia, Bulgaria (pop. 1.37 m) are among the first non-Chinese cities to test in full operation an innovative e-bus concept using capacitors, rather than batteries as energy storage.
These “ultra-capacitor” (UC) buses are fully charged at their terminal station for about 2-3 minutes, then drive their scheduled route of up to 20 km until they require another 2-3 minutes of charging. For emergencies (such as traffic jams), one stop along the route is also equipped with charging infrastructure, requiring only 30 seconds to reach necessary levels … which is about the time the bus stops for passengers.
City of Graz public transport director Barbara Muhr is excited about the new buses: “Just 2 minutes of charging for an entire run. That’s quite impressive”. Graz has put the first set of new buses from Chariot Motors in public operation on one of its lines in late 2016. Shortly, they will exchange their conventional busses of a second line with ultra-capacitor buses from Chinese-based CRRC. So far, the tests have been very successful. There were no service disruptions and even on very cold days there was no substantial reduction in range.
Without the need for batteries, the new busses can be manufactured with a considerably lower environmental impact. The lack of conventional batteries also lower the risk of on-board fires, a huge concern in public transport. With a 100% renewable energy mix, such buses are the future. I’m looking forward to seeing more of them in cities around the world.
*) Recommended read: Revolution in public transport: China’s smart bus
*) Featured image: copyright “Holding Graz”