After Gutenberg

Electric drives save more energy when the motors have the capability of switching to become generators so as to capture kinetic energy, a feature known as regenerative braking. Another trend is omission of transmissions in favor of in-wheel motors. An example is the Orion VII low-floor bus.

When the Toronto Transit Commission showed off the first of its new “environmentally friendly” bus fleet at an April 20 presentation, the Toronto Star carried the story describing those qualities that make diesel-electric, serial hybrid buses more fuel efficient, much quieter on city streets and cheaper to maintain. The benefits of the new investment include:

• An engine smaller than that used in conventional buses, running at optimum speed for clean operation and efficiency.
• Quicker acceleration, helping drivers merge into heavy traffic.
• A quieter ride than on a conventional diesel bus.
• A regenerative braking system, which saves energy and also reduces brake wear by about one-third, reducing the frequency of brake maintenance.
• The system design also eliminates the transmission, thereby removing a major maintenance item on vehicles operated in heavy stop-and-go traffic.

And, investment it is. The bill for 150 new hybrid buses “comes to $112 million, paid for by the City of Toronto, the province and Ottawa.

The hybrid buses cost about 50 per cent more than regular diesel-powered buses… But the long-term benefits should save the city money since the buses are powered through a combination of diesel fuel and electricity

The advantages of such cleaner, smarter, transit buses are that they produce:

• 37 per cent less greenhouse emissions.
• 36.3 tonnes less carbon dioxide per bus each year.
• 30-50 per cent less nitrogen oxide emissions.
• 30-50 per cent less soot particulates.
• 20-30 per cent less fuel consumption.*

* Note:

The estimates are based on New York City’s experience with the same bus. That city has 180 Orion VII’s in use now, with orders that will see more than 500 on the road by the end of the year.

“They’re working just fine,” said Paul Fleuranges, spokesman for New York City Transit. “They are performing as well as or even a little better than we expected, and doing exactly what we wanted, which is to contribute less to pollution and increase fuel mileage.”

The Orion VII buses feature the BAE HybriDrive that combines 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. The bus is built in Mississauga, Ontario at Orion Buses, a division of DaimlerChrysler.

Another step taken by the Toronto Transit Commission is to fuel their fleet of nearly 1500 buses with a biodiesel blend. According to Green Car Congress, Canadian Suncor Energy is supplying the biodiesel, which TTC has requested be lessened from B20 to B5.

So, TTC is making use of Canadian-made buses and Canadian biodiesel, perhaps the Commission may want to consider another Canadian product from Hy-Drive Technologies: H2DI. Running on biodiesel actually seems to increase NOx emissions slightly, possibly indicating that vehicle running on biodiesel blend might benefit from hydrogen direct injection to encourage more complete combustion.