As part of a multi-year research project to evaluate and improve alternative fuel technologies in the commercial sector, the U.S. Energy Department in cooperation with the United Parcel Service (UPS) just published a real-world performance study of the company’s hybrid electric delivery vans with impressive double-digit results.
UPS Hybrid Electric Vehicle. Photo courtesy of worktruckonline.com.
The performance study was conducted by a team from the Energy Department’s National Renewable Energy Laboratory (NREL), which collected and analyzed in-service fuel economy maintenance, and other vehicle performance data from 11 hybrid and 11 conventional step vans operated by UPS in Minneapolis.
“During the on-road portion of our study, the hybrid vans demonstrated a 13 to 20 percent higher fuel economy than the conventional vans, and up to a 45 percent improvement in ton-miles-per-gallon” said Michael Lammert, NREL project engineer, adding that this wide range in fuel economy was dependent on the drive cycle.
The data collection began in early 2010, culminating in a 18-month evaluation study using 11 model year (MY) 2010 Freightliner P100 hybrid step delivery vans and 11 MY 2010 Freightliner P100 conventional step delivery vans on both urban and highway routes. The two groups switched assignments during the study to provide a more balanced review of the vehicles performance.
Regarding the Minneapolis facility where the evaluations were conducted, the study reported that:
It was not necessary to modify the Minneapolis facility in any way to implement the hybrid vehicles into the fleet.
Drivers were given training on the operation of the hybrids, but no restrictions or special accommodations were made for their use; however, UPS did assign the hybrid vans to urban routes rather than rural routes to make the best use of the hybrid drive train.
The hybrid vans featured hybrid propulsion systems, including: 44 kilowatt electric motors, lithium ion batteries, and regenerative brakes that capture energy normally lost during braking to power the electric motor.
In terms of fueling, the Minneapolis facility has on-site fueling, and the vehicles were fueled by the drivers as needed, using an internal fuel card system. The drivers then logged their fueling events on their electronic tablets, and the records were uploaded to a central database.
For fuel performance, the study found that overall the hybrids demonstrated a greater advantage on the more urban, low speed, high stops-per-mile routes, and a lower advantage on the longer highway routes with less dense delivery zones.
Averaging out the combined overall fuel usage for urban and highway miles, the study found that “fuel costs per mile (assuming $3.58/gal) for the hybrids were 11 percent less than those for the conventional vans.”
It wasn’t all sunshine and roses for the hybrids though; they did have some higher maintenance costs. The study found that higher maintenance costs were driven by more labor hours in most categories with transmission related issues, which were “seven times higher than on diesel vans.”
The study also, though, said that:
This snapshot does not yield enough operating cost data to provide a complete understanding of the full lifecycle cost of the hybrid vans.
Understanding costs requires an examination of the purchase cost of the vans plus warranty and operation costs as well as long-term maintenance activities, such as engine rebuilds or replacements, and battery replacements, which also must be considered.
This analysis is not predictive of maintenance costs assumed by UPS beyond the warranty period. The exact components and warranty periods – as negotiated by UPS, Eaton, and Freightliner – are contractual and confidential. All maintenance for the Eaton hybrid drive was done by Eaton mechanics.
This has only been the latest study done in partnership between UPS and the Energy Department, which has been tracking and evaluating the performance of the company’s various generations of hybrid vehicles over the last five years.
The Energy Department says its ultimate goals include “bridging the gap between research and development and the commercial availability of advanced vehicle technologies that reduce petroleum use in the United States,” enabling fleet owners and operators to make informed vehicle purchasing decisions, and improving air quality.
The data in this study showed that carbon dioxide emissions were overall reduced on the hybrids as a result of lower fuel consumption and that “emissions on total hydrocarbons, carbon monoxide, and particulate matter were extremely low for both vehicles on all cycles, and most differences were not statistically significant.”
The study also disclosed that, “The engines for both the hybrid and conventional vehicles were the same engine family, model, model year, U.S. Environmental Protection Agency nitrogen certification level, and horsepower rating.”
UPS has been very happy with the performance of its alternative fuel fleets, including about 400 hybrids. Last month, the company announced the deployment of 40 new hydraulic hybrid vehicles – 20 in Baltimore and 20 in Atlanta.
The new hydraulic hybrids were immediately deployed in Baltimore and they will be introduced in Atlanta sometime by the end of the year.
Developed by Freightliner Custom Chassis Corp. and Parker Hannifin Corp., UPS expects the new hydraulic hybrids to “achieve up to 35 percent improved fuel economy and up to a 30 percent carbon dioxide emissions reduction over traditional diesel-powered vehicles that use automatic transmissions in stop-and-go applications.”
Both deployments are being supported in part by grants from the Energy Department’s Clean Cities program.
UPS currently operates about 2,600 vehicles powered by alternative fuels and technologies – besides hybrid electric – including electric, liquefied natural gas, compressed natural gas, bio-methane, and propane-powered vehicles.
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