Fuel Cell system drive for rotopress refuse collection truck

The rubbish collection vehicle incorporates a fuel cell energy system that is run by hydrogen. This enables the main drive (diesel engine) to be switched off during rubbish loading and compacting procedures. Rubbish is emptied into the truck’s 20 m3 drum by using a lifter to raise the rubbish bins. The waste is then compacted using electrical energy, emitting only minimal noise. In this way, up to three litres of diesel fuel are saved per hour, which translates to a reduction in diesel consumption of almost 30 %. CO2, NOx and fine particle emissions are also reduced as a consequence.

The energy produced from the 32 kW fuel cell unit can also be temporarily stored in super capacitors to cover peak loads. The hydrogen tank system consists of two 350 bar pressure canisters to store a total of 10 kg of compressed, gaseous hydrogen.

Germany’s largest municipal waste disposal company, the BSR, has been a pioneer for the testing and implementation of innovative environmental protection measures for several years. The reduction of fleet CO2 emissions is an important measure in this regard.

The electrification of auxiliary systems and units is an interesting market for fuel cell technology for several reasons:

• The switch to electrical power significantly reduces noise of exhaust emissions
• Fuel cell systems are significantly lighter than corresponding battery-based solutions
• Deployment in fleet operations is possible, thereby making the introduction of new vehicle concepts and the development of the necessary hydrogen infrastructure economically more feasible.

Besides the development of the prototype vehicle, extensive tests under real operating conditions (vibrations, dirt) to prove the system’s functional capabilities were undertaken in various weather conditions (heat, dampness, frost, etc.), as part of the project.

Test operations proved the overall operational suitability compared with conventional vehicles. Over the course of the project, the system’s winter hardiness could be substantially improved. Energy efficiency could also be continuously enhanced through the implementation of an automatic start-stop mechanism and the optimised alignment of the auxiliary systems to the specifics of the electric drive. Outstanding issues for a wider market introduction include the increase of payload to over 11 t and the improvement of the small series availability of components such as:

• Starters for heavy-duty commercial vehicle applications in refuse collection
• Electric lift systems for receptacles
• Integration with propulsion drivetrain (hybridisation)
• Electrification of the air conditioning (place of work), oil pump, etc.

In addition, the energy management system must be improved and reductions in cost must be realised.