Trucks at Work
Hybrid expansion

Hybrid expansion

Got a chance to spend some time with Eric Smith this week: Eaton Corp.‘s chief engineer for special projects and hybrid-electric systems. Right now, he‘s working on the second generation of Eaton‘s parallel hybrid system, used on medium-duty commercial trucks right now usually in conjunction with diesel engines.


“What we‘re trying to do now is expand hybrid technology into other trucking applications,” he told me. “That means we‘re not only refining the technological package as a whole to lower its cost and produce better fuel economy, but also make it a more ‘multi-purpose‘ system, so we can use the hybrid‘s batteries for tasks other than just propulsion.”

Smith pointed to Eaton‘s involvement with the HTUF hybrid truck project back in 2004 as an example of that expansion. That effort resulting in a utility bucket truck that could tap into the hybrid system‘s battery to run the boom lift at a work site, allowing for “engine off” operation for up to two hours at a time before the diesel motor had to fire up for five to 10 minutes to recharge the batteries.

“The biggest challenge we have with hybrids is ROI [return on investment] for fleets,” Smith told me. “It‘s all about how we justify the extra cost of a hybrid to them. One part is fuel economy: fleets are feeling the pain of diesel fuel prices up over $3 a gallon. The other is capability; that helps expand the ROI. We‘re looking at putting a 110-volt generator on the truck, tapped into the hybrid batteries, providing power for a contractor‘s tools. Another thing we‘re looking it is powering refrigeration systems, to give refrigerated carriers ‘engine off‘ capability when making deliveries.”

Expanding a hybrid‘s capabilities drives costs savings - and that‘s critical to getting fleets to buy more of them. For the higher the production volumes, the lower the manufacturing costs - and thus the lower the premium for a hybrid truck, said Smith.

Eaton is also looking at other vocations where hybrid systems could play a wide role. Delivery vans and utility trucks were an obvious - and ultimately successful - market to start in. Eaton formed its hybrid power systems business unit back in 2000 and quickly landed a contract from FedEx and public interest group Environmental Defense in 2002 to build 18 hybrid step vans. That contract has grown significantly, with FedEx subsequently ordering 75 more of the E-700e hybrid vans in 2005 that will start entering its fleet by the second quarter this year.

UPS and the Department of Energy quickly followed suit in 2004 with an 18-vehicle order of their own, and those demonstration units are still going strong, with the oldest truck - now four years old - still plying hilly routes in San Francisco. UPS is also moving to beef up its hybrid fleet, with 50 more of those vans on order.

Eaton partnered with China bus maker Foton in 2006 to built hybrid transit buses - rolling 30 of them out of the factory and onto the streets of Guangzhou at the end of last year - and has entered into deals with Peterbilt, Kenworth, International, and Freightliner to build more medium-duty hybrid trucks. It also has an exclusive deal with Paccar to build Class 8 hybrids as well.

Right now, fuel economy savings and a tax credit to offset the purchase price are what‘s attracting fleets. While the $12,000 tax credit is universal, the fuel savings differ by vehicle type and operation, Smith stressed. For example: a hybrid medium-duty utility truck can see a fuel savings of 60% and reduced idle time of 87%, while a city delivery van posts a fuel savings of 50% and a city bus gets a fuel savings of about 20% to 30%.

In the Class 8 world, the fuel savings are trickier to achieve because of its steady-state, highway-driving environment. But with the hybrid system aiding with acceleration and on hills, while reducing idling, a fleet could save up to $9,000 in operating costs per truck per year, according to Eaton‘s laboratory and road tests.

“The thing is, driver habits vary so widely in the real world,” he told me. “We use dyno testing in the lab to provide us consistent data in terms of what the potential fuel savings are. Then you perform field tests to see how the truck really gets used. For example, does the driver shut off the diesel engine when he or she stops to make a delivery? That really impacts the final fuel savings result you‘ll see.”

Despite those challenges, though, Smith is confident that hybrid commercial trucks will continue to come down in cost, while returning more savings to fleets. “We‘re improving cost efficiency, reliability, and durability with each successive generation of hybrid system,” he said. “We‘ll still have a lot of room to really ‘tune‘ hybrid trucks to their particular work environment so they save fleets as much as possible across the board.”