Energy consumption and GHG emissions evaluation of conventional and battery-electric refuse collection trucks
Date
2019-12-09
Authors
Derakhshan, Rojin
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Abstract
The notorious fuel consumption and environmental impact of conventional diesel refuse
collection trucks (D-RCTs) encourage collection fleets to adopt alternative technologies
with higher efficiency and lower emissions/noise impacts into their fleets. Due to the nature
of refuse trucks’ duty cycles with low driving speeds, frequent braking and high idling
time, a battery-electric refuse collection truck (BE-RCT) seems a promising alternative,
taking advantage of energy-saving potentials along with zero tailpipe emissions. However,
whether or not this newly-introduced technology can be commercially feasible for a
collection fleet and/or additionally mitigate GHG emissions should be examined over its
lifetime explicitly for the specific fleet. This study evaluates the performance of a D-RCT
and BE-RCT in a collection fleet to assess the potential of BE-RCT in reducing diesel fuel
consumption and the total GHG emissions.
A refuse truck duty cycle (RTDC) was generated representing the driving nature and
vocational operation of the refuse truck, including the speed, mass, and hydraulic cycles
along with the extracted route grade profile. As a case study, the in-use data of a collection
fleet, operating in the municipality of Saanich, British Columbia (BC), Canada, are applied
to develop the representative duty cycle. Using the ADVISOR simulator, the D-RCT and
BE-RCT are modeled and energy consumption of the trucks are estimated over the
representative duty cycle. Fuel-based Well-to-Wheel (WTW) GHG emissions of the trucks
are estimated considering the fuel (diesel/electricity) upstream and downstream GHG
emissions over the 100-year horizon impact factor for greenhouse gases. The results
showed that the BE-RCT reduces energy use by 77.7% and WTW GHG emissions by 98%
compared to the D-RCT, taking advantage of the clean grid power in BC. Also, it was
indicated that minimum battery capacity of 220 kWh is required for the BE-RCT to meet
the duty cycle requirements for the examined fleet. A sensitivity analysis has been done to
investigate the impact of key parameters on energy use and corresponding GHG emissions
of the trucks. Further, the lifetime total cost of ownership (TCO) for both trucks was
estimated to assess the financial competitiveness of the BE-RCT over the D-RCT.
The TCO indicated that the BE-RCT deployment is not financially viable for the
examined fleet unless there are considerable incentives towards the purchase cost of the
BE-RCT and/or sufficient increase in carbon tax/diesel fuel price. From the energy useevaluation, this study estimates the required battery capacity of the BE-RCT for the studied fleet, and the TCO outputs can assist them in future planning for the adoption of battery-electric refuse trucks into their collection fleet where the cost parameters evolve.
Description
Keywords
Refuse collection truck, Representative duty cycle, WTW GHG emissions, Total cost of ownership (TCO)