Analysis of energy-storage concepts for refuse collection trucks

Four hybrid powertrain designs are compared for a refuse collection truck driven over approach, loading and return segments of a representative route. Appropriate matching of component characteristics, drivetrain design and control strategy is shown to reduce fuel consumption by 39% to 56% compared to a conventional vehicle. Concurrently, brake usage is reduced 54% to 85% and the number of engine revolutions is reduced 66% to 84%. The four hybrid powertrains consist of ''Integrated'' and ''Add-On'' designs using flywheel or accumulator energy storage to recover braking energy and optimize engine efficiency. The average engine efficiency for each design is comparable and the vehicle fuel economy depends on the ability of each design and control strategy to minimize parasitic losses and use of the service brakes.