>>1185463>those 8 lane chinese boulevardsThis is exactly the reason why they probably don't need overhead line (since catenary is a very specific type of OHL). The trams aren't running into mixed traffic, indeed, they're running on dedicated track, which means that all they need to do is accellerate, coast while expending little power to maintain speed and then slow down for the next stop.
Meanwhile, in a European city, trams will be in mixed traffic, meaning they will be stopping for traffic lights, they will be stopping for cars and other traffic at give ways, they will be stopping in traffic, especially during rush hour and they will be stopping for obstacles in the road. European trams do a hell of a lot of accelerating and decelerating. This makes having an OHL much, much more vital for smooth operations. In China, they might only need to accelerate, keep at speed and then only stop for a tram stop.
Pic related is a comparable system, the Gyrobus. Using a flywheel for energy storage, the bus would charge up using trolley poles like a trolleybus, but then use the power from, the flywheel to go from stop to stop. The Chinese trams are likely using a system that isn't too far off.
