The San Francisco Municipal Transportation Agency (MUNI) has accepted the first of 56 diesel-electric hybrid Orion VII low floor buses from DaimlerChrysler Commercial Buses. The new bus is California’s first series production diesel-electric hybrid bus in transit service.
After the official roll-out in fall 2006, San Francisco will feature the third-largest hybrid bus fleet in the country.
The selection of new diesel-electric hybrid buses capped an effort that began with MUNI’s Alternative Fuel Pilot Program of 2001-2003. Thereafter, MUNI worked extensively with the California Air Resources Board to obtain changes in the regulations, unanimously adopted in 2006, that enabled the acquisition of these buses.
The Orion VII hybrid bus, powered by BAE Systems’ HybriDrive series propulsion technology, has logged more than 10 million in-service miles in highly demanding cities such as New York and Toronto.
The Orion VII series-hybrid 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 electric traction motor delivers 250 hp (186 kW) and 2,700 lb-ft (3,657 Nm) of low-end torque.
A study by the National Renewable Energy Laboratory found that the Orions in service in New York City—the largest fleet—achieve up to 45% better fuel economy compared to conventional diesel buses. Additionally, the Orion VII greatly reduces emissions: 90% less particulate matter, 40% less NOx, and 30% fewer greenhouse gases. (Earlier post.)
After the delivery of the full order, electric-hybrid buses will constitute 11% of MUNI’s bus fleet. In conjunction with other buses such as trolleys, MUNI will then feature an electric fleet of well over 50%.
DaimlerChrysler Commercial Buses North America combines three bus brands under one corporate structure: Orion transit buses, Setra motor-coaches, and the Dodge Sprinter shuttle bus.