Hybrids and Alternative Fuels Deliver the Goods

High profile delivery fleets including the U.S. Postal Service (USPS), FedEx Express, United Parcel Service (UPS), and Purolator have hundreds, even thousands, of alternative fuel vehicles (AFVs) in daily use. They are also leaders in using hybrid electric, hydraulic hybrid, and fuel cell vehicles in their delivery fleets. USPS has the nation's largest AFV fleet, numbering some 37,000 vehicles. The UPS fleet includes over 1,600 "green" vehicles, making it the largest private AFV fleet in the transportation industry.

While not as glamorous as hydrogen fuel cells, natural gas vehicles (NGVs) are a popular and readily available technology that's displacing petroleum use and cutting emissions every day. USPS has converted 7,300 of its long-life vehicles used in mail delivery to run on compressed natural gas (CNG) and another 35 to run on propane. The USPS fleet also includes over 50 CNG two-ton mail pickup vans.

UPS operates over 800 CNG fueled trucks in the U.S. and recently ordered 167 more. It also uses nearly 600 propane fueled trucks in Canada and Mexico and is adding another 139. While the CNG and propane trucks currently in the UPS fleet were converted from gasoline and diesel vehicles in the 1980s, the new trucks have been designed from the ground up to run on the alternative fuels. Two sizes of Freightliner Custom Chassis Corp. trucks powered by Cummins Westport engines are being purchased.

At the turn of the century, Thomas Edison forecasted that "vehicle transportation in cities will ultimately be done by electric storage battery vehicles." Indeed, the U.S Post Office used electrically powered delivery vans quite extensively prior to World War I and experimented with vans like the "ElectroMail" and "Electrotruck" in subsequent years. Today, USPS has 30 electric Azure Citivans, two-ton delivery trucks used to transport mail and bulk packages in New York City. Likewise, UPS used a fleet of electric trucks in New York City in the 1930s and is currently using several CNG package cars.

Purolator, Canada's largest overnight courier company, has worked with Unicell Limited and ArvinMeritor to develop the Quicksider all-electric urban delivery vehicle. This prototype urban delivery vehicle uses a lightweight fiberglass body mounted on a stainless steel chassis. It has a pneumatic suspension system that enables the truck to "kneel" in the rear for easier loading and unloading. Two electric motors delivering 230 horsepower are currently powered by ZEBRA sodium nickel chloride (NiCl) batteries, although Electrovaya is developing a lithium-ion polymer replacement.

The world's oldest and largest electric vehicle manufacturer, England's Smith Electric Vehicles, plans to market a 12-ton GVW Newton electric truck and 3.5-ton Edison based on the Ford Transit van to North American fleets. Enova Systems in California will supply the 120 kilowatt electric drive system for the Newton along with four Zebra Z5 NiCl batteries. The smaller Edison, intended for postal and parcel delivery work, features Enova's 90 kilowatt drive system and also uses NiCl batteries.

Hybrid electric delivery trucks, which are growing in popularity, are also not that new. For example, between 1938 and 1942 Walker Electric Trucks produced the Dynamotive. This series hybrid gasoline-electric truck definitely fits the definition of a hybrid.

FedEx Express has the largest fleet of hybrid-electric delivery vehicles in the U.S. This includes 93 OptiFleet E700s developed with Environmental Defense and Eaton Corp., which use the familiar FedEx W700 model with a Freightliner chassis and Utilimaster body. Its parallel hybrid electric propulsion system replaces the six-cylinder diesel with a four-cylinder diesel and an electric motor supplying additional power. Batteries store energy from regenerative braking and provide electric power to the motor when needed. An additional benefit is that fleet operators are finding regenerative braking reducing brake wear and subsequent brake maintenance.

FedEx Express contracted with Azure Dynamic to develop a gasoline parallel hybrid electric powertrain for use in a delivery truck based on the Ford E-450 van. FedEx Express will purchase at least 20 of these vans to be delivered by May 2008. Purolator operates 49 hybrid-electric delivery vehicles supplied by Azure Dynamics with another 75 to be delivered by the end of 2008.

UPS is operating 50 delivery vans powered by an Eaton Corp. electric hybrid propulsion system. The vans are manufactured by Workhorse Custom Chassis and Freightliner Corp. The hybrid system employs an Eaton automated transmission, an integrated motor/generator, and advanced lithium-ion batteries. The Freightliner model has a Mercedes-Benz four-cylinder diesel engine, while the Workhorse model features an International six-cylinder diesel.

USPS is evaluating in service a prototype series hybrid electric Carrier Route Vehicle converted by Azure Dynamic. Today, USPS also uses 10 Ford Escape Hybrids for mail delivery.

It may look any other brown UPS package car until you notice "Low Emissions Hydraulic Hybrid" lettered on its side. This demonstration vehicle was developed through a partnership between the Environmental Protection Agency, Eaton, UPS, International Truck and Engine Corp., and the U.S. Army. In this series hydraulic hybrid truck, a high efficiency International V-8 diesel engine is combined with a hydraulic propulsion system to replace the conventional driveshaft and transmission.

Hydraulic hybrids are well suited for the frequent start-stop duty cycle of delivery trucks. Eaton's Hybrid Launch Assist (HLA) technology has been developed for both series and parallel hybrid configurations. The series hydraulic hybrid gains its improved fuel efficiency through regenerative braking, by operating the engine at its optimum rpm, and by shutting the engine off when not needed. A high-pressure accumulator and low-pressure fluid storage tank are used. A hydraulic pump connected to the engine pressurizes the system, while a combination pump/motor connected to the differential drives the wheels and recoups kinetic energy when braking.

In 2004, UPS deployed three Dodge Sprinter package delivery vehicles powered by hydrogen fuel cells in Los Angeles, Sacramento, and Ann Arbor (Mich.). It also tested a fuel cell-powered Mercedes-Benz F-Cell, based on the diminutive A-Class car, which was modified for early-morning package deliveries in southeastern Michigan.

Both USPS and FedEx Express have evaluated General Motors HydroGen3 fuel cell minivans in delivery service. In Canada, Purolator is demonstrating a fuel cell hybrid delivery vehicle developed by Azure and Canadian hydrogen fuel supplier Hydrogenics Corp.

Package delivery services are a proven route to fleet testing the technologies and fuels that could radically decrease emissions and energy use. Importantly, these services are a high-profile part of our daily lives and they're readily recognizable on the street, which means that public awareness of alternative fuels and advanced drivetrains comes as an important bonus.