Just over a year ago I talked in this column about whether or not hybrid vehicles made economic sense. Sure, slaving a diesel or gasoline engine to an electric motor and battery pack obviously reduced emissions and saved fuel, but did it save enough fuel to make it worth the extra cost?
It was a discussion that revolved around light-duty hybrids — not medium or heavy-duty hybrid trucks, which seemed to be stuck in the prototype stage.
That is no longer the case. Though still in their infancy, medium- and heavy-duty truck hybrids are on a roll. Kenworth, Peterbilt, Mack, Freightliner and others have partnered with a wide variety of suppliers to make commercial-grade hybrids a reality. And they should pay for themselves by combining fuel savings with a variety of cost-defraying advantages offered by federal, state and local agencies.
“Hybrid technology is finally robust enough for commercial trucks,” Dan Kieffer, research and development manager for Kenworth Truck Co., told me during the Mid-America Trucking Show. “In a P&D application, the hybrid configuration can improve fuel economy by 30%. We believe incentives and tax credits can offset most if not all of the additional cost for hybrid trucks, with the fuel savings making up any difference quickly.”
Kenworth plans limited production of its T270 medium-duty hybrid for municipal fleets and utility companies this year, with full-scale production expected to follow in 2008.
“During steady driving conditions above 30 mph, the T270 hybrid operates like a standard diesel vehicle with all power coming from the engine,” says Mike Dozier, Kenworth's chief engineer. “Below 30 mph, it uses a combination of diesel and electricity — automatically switching between the two modes. Basically, the more stop-and-go operation in the application, the better this truck's performance.”
The system also stores the energy given off during regenerative braking and re-uses it to help with acceleration, all while reducing brake wear by 30% to 50%, says Kieffer: “There's a reduction in brake wear because the electric generator produces braking energy.”
Peterbilt Motors Co. is taking an even broader stab at hybrids by developing and testing four distinct vehicle applications, says Landon Sproull, the company's chief engineer: Hybrid-electric heavy-duty vehicle for long-haul work; a medium-duty for P&D; a medium-duty equipped for stationary PTO applications; and a hydraulic-hybrid heavy-duty vehicle for vocational and stop-and-go applications.
“Each of these vehicle platforms addresses unique customer concerns to reduce operating expenses and comply with various regulatory requirements,” Sproull points out.
Limited production on these models, except the Class 8 version, begins this year, followed by full production in 2008. Peterbilt is developing the Class 8 hybrid with Eaton for Wal-Mart. Currently undergoing field tests, it should be market-ready by 2010, Sproull says.
“The key thing here is that hybrids are no longer just for small trucks in city applications; the technology is viable for big vocational vehicles as well,” Paul Vikner, president and CEO for Mack trucks told me at a special event in Washington, DC, earlier this year that showcased a Mack Class 7 hybrid Granite dump truck.
“Obviously, the initial cost of the technology and how its affects the cost of operations are the big concern of customers now. If they can see benefits beyond fuel economy — reduced brake and engine wear, less pollution and noise — and we can establish the reliability of hybrid systems in their application, it'll help commercialize this technology at a much faster pace,” said Vikner.