The Alternative Fuel Vehicle Institute’s National Conference and Expo 2007 held in April in Anaheim, Calif., featured a session on the state of the heavy-duty plug-in hybrid market and whether the technology is close to commercialization.

There was no debate over whether or not plug-ins are a viable option, but session panelists predicted when they would be widely available and what barriers stand in the way.

The panelists spoke about their organizations’ efforts toward commercialization of plug-in hybrid electric vehicles (PHEV), stressing the effectiveness of research and development done through deployment programs.

The panelists all agreed that PHEVs are well suited to heavy-duty applications because their implementation would address rising fuel costs, aging fleets and environmental impact.

Odyne Corp. CEO Roger Slotkin explained that his company makes PHEV powertrains for new and older fleets, which he says are ideal for stop-and-start vehicles such as delivery vehicles and transit, school and cutaway buses. Odyne’s vehicle systems range from 20,000 to 30,000 pounds, said Slotkin, and the plug-in system is available for trucks, buses and other class 6, 7 and 8 vehicles.

Slotkin describes Odyne as being “fuel agnostic,” as they can handle conversions for vehicles that use any type of fuel to power the system’s generator, as well as all-electric applications. “The engine provides cruising power at constant rpm while reducing emissions and fuel consumption,” Slotkin said. One of Odyne’s first PHEV applications was for an ElDorado transit-style bus that was all-electric capable, including the air conditioning system.

Odyne’s PHEV powertrain uses the engine as a powerplant, Slotkin said, and any type of engine can be upfitted as a plug-in. The engine charges the batteries, with additional help from brake regeneration. Because Odyne can retrofit old vehicles, operators save on the cost of purchasing new vehicles, plus the additional fuel savings. “An electric mile is about 20% of the cost of a diesel mile,” Slotkin said.

Slotkin also noted that Odyne offers a variety of storage sizes, as well as the choice of either a charge-depleting versus a charge-sustaining system so operators can build a vehicle that best meets their needs.

“We allow fleet managers to access plug-in technology today, not years from now,” Slotkin said. Odyne’s end users include municipal transit agencies, refuse collection companies and organizations requiring shuttle buses.

While the first PHEV transit bus Odyne made cost $1 million, Slotkin notes that because battery and engine technologies are robust and rapidly evolving, costs are coming down. He said these days Odyne can produce a similar vehicle for about an eighth of the original cost, or $125,000.

Mark Duvall, representing the Electric Power Research Institute (EPRI), explained that the No. 1 barrier to widespread deployment is battery technology and the high costs involved.

EPRI works to directly contribute to the commercialization of PHEVs on a significant level, Duvall said, by gathering funding from partnerships with manufacturers and energy utilities to support research and development.

The automakers in the partnership then take on vehicle development, building prototypes and preparing for production if the PHEV model is found to be viable. Because PHEVs are ideal for vehicles that travel about 20 miles a day in stop-and-go traffic, Duvall said, EPRI is currently running a Sprinter Van program with DaimlerChrysler Commercial Buses N.A.

International Truck and Engine Corp. is involved with the manufacture of both school and commercial buses and is strongly interested in the commercialization of plug-ins. Randall Ray, manager of bus product development, said that the lithium ion batteries being developed are ready to be put on the road. “We’re looking for consistent and sustainable volume,” he said. Investment in lining up a supply chain is key to getting to commercialization by 2010 and widespread use by 2020, he added.

In a partnership with Advanced Energy, International is producing 19 PHEV school bus units for 11 buyers. As an OEM, Ray says International can validate all the technical systems on the bus, and brings the resources of service, technical support and a network of dealerships to the market. “We are ready for production,” he says. “We can take orders, we can build.”