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NREL Follow-up Evaluation Quantifies Fuel Savings in Hybrid Electric Delivery Vans

April 24, 2012

NREL fleet test and evaluation engineers recently completed a three-year technology evaluation of hybrid electric vans compared with conventional diesel vans. A new report authored by Mike Lammert and Kevin Walkowicz of the Center for Transportation Technologies and Systems details the team’s efforts to determine the impact of hybridization on fuel economy and performance. 

“We collected and analyzed fuel economy, maintenance, and other vehicle performance data on six hybrid vans and six conventional vans used for parcel delivery service by the United Parcel Service in the Phoenix, Arizona, area,” said Walkowicz.

The hybrid vans demonstrated 23% higher fuel economy than the diesel vans, resulting in a 19% reduction in fuel costs for the hybrids. The reliability of the hybrids was slightly lower (96.3% compared to 99%), primarily due to troubleshooting and recalibration issues related to prototype components. Differences in per-mile maintenance and operating costs were not statistically significant.

Manufactured by Freightliner, the hybrid vans featured hybrid propulsion systems produced by Eaton Corp. with 44kW electric motors, regenerative braking, and lithium-ion batteries. The comparable conventional vans, also manufactured by Freightliner, were approximately the same age as the hybrid vans and were operated under the same conditions.

“This evaluation was a continuation of a study we performed in 2008 when the United Parcel Service first added these first-generation vehicles to its fleet,” Walkowicz added. “And now we’re in the process of an 18-month evaluation of the company’s second-generation hybrid vans operating in the Minneapolis, Minnesota, area.”

NREL has been tracking and evaluating new propulsion systems in transit buses and trucks for more than 10 years. These evaluations are part of the Advanced Vehicle Testing Activity, which supports DOE’s Vehicle Technologies Program. Learn more about NREL’s fleet test and evaluation projects.

—Julia Thomas