Although both FedEx and United Parcel Service are field-testing hybrid-electric vehicle (HEV) technology in package delivery trucks, the two are putting large-scale adoption of that technology on hold because of high lifetime operating costs, according to a report in the newsletter Ward’s Engine and Vehicle Technology Update. Instead it appears that they and other commercial fleet operations are awaiting further development of hydraulic-based hybrid systems.
The hydraulic approach could offer significantly lower lifetime operating costs, perhaps as low as one-third the cost of HEV, sources told the newsletter. The HEV approach stores energy in battery packs that must be replaced periodically. Hydraulic hybrid systems store compressed-fluid energy in an accumulator that does not need replacement. The hydraulics are also more efficient in capturing energy for storage and less complex.
Hydraulic hybrid systems are currently in development for refuse collection trucks by Eaton Corp. and Dana Corp.
The newsletter says both package delivery companies do report good operating results from their prototype HEVs. A UPS HEV in service since 1999 make 150 stops a day traveling a 31-mi. route. FedEx is currently putting 20 HEVs into service this year for a field trial. The two declined to discuss the hybrid alternative with the newsletter, expect to say it is being considered.
FedEx has 30,000 delivery trucks in the U.S., and UPS operates 77,000 of its “Brown Vans” in domestic service.