FEDEX buys hybrid vans from Azure Dynamics
Wednesday, May 30th, 2007 - 11:41 am
FedEx Express has signed agreements with Azure Dynamics Corporation to develop gasoline parallel hybrid-electric powertrains for their delivery fleet. Azure will supply a parallel hybrid-electric test vehicle to FedEx Express for the Ford E-450 hybrid commercial delivery van development program. FedEx Express has committed to purchase a minimum of 20 pre-production parallel hybrid-electric Ford E-450 delivery vans to be delivered by May 2008 following the development project.
FedEx Express currently has 93 hybrid-electric vehicles in service in North America that have altogether traveled more than one million miles.
Azure’s largest sale to date, in October 2005, was for 115 series hybrid-electric vehicles to Purolator Courier, but I don’t know how many have been delivered or how many remain in service.
Azure Dynamics started out in Vancouver, before moving its head office (HO) to Toronto. Earlier this month, the company announced plans to close the Toronto HO, as well as its UK Kenilworth office and service centre. It will open a new HO in the Detroit/Windsor area, or possibly Ohio, in order to be closer to Ford and other auto manufacturers. (Source: Azure Dynamics)
Hybrid Drives — Not All the Same
In a parallel hybrid electric vehicle design, the addition of computer controls and a transmission allow both the engine and electric motor to generate the power required to drive the wheels according to the prevailing driving conditions. The internal combustion engine is able to charge the battery or connect directly to the wheels, avoiding the inefficiency of converting mechanical power to electricity and back. Electric power can be used when required, most often during low-speed urban driving. Power from both the engine and electric motor can be combined for accelerating.
The advantage of parallel hybrid platforms is they can cruise more efficiently at highway speeds using only the engine, but still regenerate energy in the brake cycle and, like a series hybrid, use no energy when stopped.
Conversely, in a series hybrid electric vehicle design, the electric motor is the only means of providing power to the wheels as the internal combustion engine is not directly connected to the drivetrain. The motor receives electric power from a battery pack or from an on-board generator (genset) powered by the engine and a computer determines the amount of power delivered from the battery or the genset. Batteries in a series hybrid are recharged by the genset and regenerative braking energy. Such vehicles are generally considered unsuitable for highway applications.
The Toyota Prius, undoubtedly the most commercially successful hybrid, uses a combination parallel-series drive. Toyota’s “Hybrid Synergy Drive” is only one example of this strategy that decouples the power supplied by the engine (or other primary source) from the power demanded by the driver. It incorporates a planetary gear as a power-split device allowing for power paths from the engine to the wheels that can be either mechanical or electrical.
A full comparison of the advantages and disadvantages of the different hybrid implementations is beyond the scope of this article. See the Wikipedia entry “Hybrid vehicle drivetrains” for a fuller explanation with schematic diagrams.
