As anticipated (earlier post), the Toronto Transit Commission (TTC) has ordered 150 series hybrid diesel-electric buses from Orion Bus Industries, a division of DaimlerChrysler. The hybrids are part of a larger 330-bus order.
These buses, to be delivered in 2006, will be TTC’s first hybrid models and will give Toronto the largest hybrid electric fleet in Canada.
New York City, which operates North America’s largest bus fleet, has 125 Orion hybrid buses already in service with 200 more being built, to be in service by the end of this year. Seattle has the largest in-service hybrid fleet in the world, with 210 buses manufactured by Winnipeg-based New Flyer.
Unlike the New Flyer buses, which use the GM-Allison parallel hybrid drive, the Orion VII buses are series hybrids, using a propulsion system from BAE Systems.
The Orion VII buses with the BAE HybriDrive combine a 5.9-liter, 260 hp (194 kW) Cummins ULSD (Ultra Low-Sulfur Diesel) engine with a 120 kW traction generator. The traction motor delivers 250 hp (186 kW) and 2,700 lb-ft (3,657 Nm) of low-end torque.
Regenerative braking recharges the lead acid batteries used for energy storage. The series hybrid design eliminates the transmission, removing a major maintenance item on vehicles operated in heavy stop-and-go conditions and eliminating the jarring shift points common among conventionally propelled buses.
Compared to conventional diesel propulsion, the hybrid units will provide 25%–35% better fuel economy. New York City transit reports average operational gains in fuel efficiency of 28% over conventional diesel buses.
Emissions reductions are substantial: 90% less particulate matter, 40% less NOx, and 30% fewer greenhouse gases.