What’s accelerating electric trucks’ potential as a mainstream alternative to a diesel-powered truck? Answer: batteries. After years of struggling to get the power density up and the cost and weight down, thanks to the latest generation of lithium ion batteries all-electric heavies are looking increasingly operationally viable, rather than simply technically possible, especially at the heavy end.
In Germany, Munich-based truck manufacturer, MAN, has been working on all-electric heavies. At the Hanover truck show it launched its City Truck concept prime mover, intended for inner-city night-time supermarket delivery work running at a combined gross weight of 18-tonnes. The battery-powered semi is based on an existing 4×2 TGS BLS-TS prime mover, but with its normal diesel drivetrain replaced by a 250 kW electric motor that delivers its 2700Nm of torque to the drive-axle via a conventional prop-shaft.
Electrical power is supplied by three 35.3 kW/h high-performance lithium-ion batteries fitted below the cab where a diesel engine would normally sit. With the weight of the batteries over the front-axle, MAN says the full load-capacity of the rear axle can be used for the payload. “The additional weight of the electric-drive components is compensated for by dispensing with the conventional diesel engine, with the result that the vehicle has the same payload as a similar, conventional semitrailer prime mover from the TGS model range.”
Depending on usage, the City Truck’s battery-capacity permits a daily range of 50-150 km. Although its batteries are normally charged overnight they can also be ‘opportunity charged’ during a vehicle run, like when the driver takes a break, or during loading/unloading, thereby providing greater operational flexibility.
The concept prime mover can also be fitted with up to four more 35.2 kW/h battery modules on the side of the frame and/or a range-extender power unit or fuel-cell, likewise chassis-mounted, further increasing its range. The power-steering pump, air compressor and air-con are all electrically-operated while a dash-board display advises the driver on battery charge, energy recovery and charging mode.
MAN says its all-electric TGS prime mover is intended to operate with an urban semi trailer equipped with a steering single-axle and that it, ‘Fulfils the main demands being placed on future delivery vehicles for city centre applications, namely they must have a high load volume and a low unladen weight, be emission-free (in terms of CO₂, NOx and noise) when on the move and at the same time have good manoeuvrability.’
When might we see a Lion-badged all-electric semi in series-production? MAN reckons, “The eTruck Study presented at the IAA will enable MAN to implement additional testing in the field of electrically-powered trucks and gain valuable experience with real transport concepts. It represents just one aspect of the eMobility strategy from MAN Truck & Bus and offers a glimpse of the city centre transport solutions due to be part of MAN’s product range as of 2021.”