Every liter of diesel saved counts. For freight forwarders, fuel represents the second largest cost after the driver’s salary. It’s no wonder that truck manufacturers today are all trying to determine whether electrified tractors have a positive cost-benefit ratio. So far, there has been little attention on the trailer, which still usually lacks its own drive. However, with the development of two electrified trailer axles, SAF-HOLLAND is now demonstrating that electric drives can also be worthwhile in a trailer. The commercial vehicle supplier has developed two concepts. The first is the SAF TRAKr, which has a capacity of 30 kWh and briefly up to 50 kWh and works as a generator during braking. The electricity obtained can be used to power electrical equipment in the trailer, such as a refrigeration unit. This differs from the second concept – the SAF TRAKe – which temporarily relieves the tractor and has a maximum capacity of 120 kWh.
Even the small e-machine in the SAF TRAKr can achieve considerable savings. Until now, diesel generators have been used for refrigerated trailers, which must also run while stationary, so that temperature-sensitive cargo does not spoil. If these generators were temporarily replaced with battery-powered electric machines, not only would the forwarder benefit, but also the environment. Battery-powered electric machines emit no exhaust fumes and significantly lower noise. This is not a niche application either: every fifth newly registered trailer in Europe today is equipped with a cooling unit. The amount of fuel saved when using the TRAKr depends on the respective application. “There are several factors involved,” explains Olaf Drewes, who is responsible for Advanced Research & Technology at SAF-HOLLAND. “The cooling capacity required can differ considerably, depending on the region and the season.” The more powerful SAF TRAKe is always the option used when a particularly powerful drive is required, for example when a truck is driving uphill and has to accelerate. The electric motor provides up to 4,100 Nm additional torque to the wheels at lightning speed. The additional support is also welcome when a truck and trailer combination is in the inner city and needs to operate purely electrically to protect residents from the noise of delivery trucks. SAF Holland sees some interesting applications not only for food but also for automotive transporters. In the latter, the electric drive in the trailer could also quietly power the hydraulics for the lift pump.
This is an advantage when loading and unloading the transporter in the city because deliveries can then take place at night. LOHR Industrie is working together with SAF-HOLLAND and the SAF TRAKe to make these types of applications a reality.