City buses doesn’t have to be noisy, polluting and gas-guzzling anymore in the future. Volvo affirmed that last year by introducing its hybrid-electric bus 7900 at the International IAA Commercial Vehicles show last September. The hybrid bus is already under trail operations in few European cities and are the series production is scheduled for early 2016. The Volvo Bus City Mobility Team is constantly working on new technologies, focusing more on energy management and extended pure-electric drive range. One such is the Volvo’s new Zone Management system.
To start with, the Volvo 7900 Hybrid bus has an 150 Kw electric motor powered by a 19 kWh litium-ion battery to help a comparably small diesel engine. Akin to plug-in hybrid car, the bus can be charged via over-head power outlets at charging stations. A full recharge may take just 6 minutes roughly speaking. This results in a whooping 75% fuel saving, 60% energy reduction, and 75% Co2 reductions as per company. A silent, cleaner, and fuel efficient city transportation is what Volvo aims for with this bus.
Where the newer models would take lead are in the dependence on the electric motor than its hybrid predecessors. With three more batteries installed on the roof, the total of four batteries on-board can extend the pure-electric mode for approximately 8 kilometers. This can flex the vehicle’s scope for the Volvo’s new Zone management system.
Zone management is very simple. May not be so in our land, but several European cities have certain routes and zones earmarked as ‘noise-free’ or ‘zero-emission’ or even ‘safety zones’ (as in case of a school or a hospital), where applied restrictions on use of conventional vehicles. Volvo’s new system involves a GPS interface and the driver selects the route to drive through. The system then notifies him whenever he enters certain sensitive zones using the GPS. But what is influential is that the system intuitively interacts with the engine and shuts off the diesel engine automatically on entering the ‘zero-emissions’ or ‘silent’ zones, running further purely on electric. It can also slow-down the vehicle’s speed as per zone restrictions without driver’s knowledge.
The system then calculates how much distance left in the route and decides whether to turn-on the ICE or run solely on electric motor until the next charging station. It also ensures that the diesel engine boosts the electric drive to climb any significant incline, if any, on the route. Thus, the bus is at any case not left with power deficiency, while optimizing the energy used. These zones can be over-lapping or altered, yet the system is designed to work with flexibility so that they suit specific requirements of different cities and fleet.
On the whole, the company’s aim to be as efficient as possible all through the drive is effectively met. The ability to turn of ICE to run exclusively on the electric motor whenever possible is interesting, since this can have a phenomenal effect in the urban transit emissions management. This system also hints at the broadening scope of hybrid bus technology. Moving CV segment over to electric is a challenging and pricey affair, but once achieved, their outcomes can make significant differences. More so in an urban setup, because, when we ask people to use public transit instead of their vehicles, those systems have to sustainable at first isn’t it??
Photo and Video Credit: Volvo Buses