Make no mistake. Hybrid trucks and alternative fuel technologies are going to play a big part in road transport in the coming years. The burgeoning science is stimulated by the insatiable drive to reduce emissions and slash dependence on fossil fuels. The promise of major fuel savings (30-60% less petroleum consumption than conventional gas or diesel engines), has OEMs sprinting to get products on the market.

It’s been 10 years since the Toyota Prius was introduced in Japan. Today’s hybrid cars are the most fuel-efficient vehicles on the road. And commercially, light-weight urban delivery hybrids have already demonstrated their worth. To date, most of the major courier giants have active hybridization programs in place with a couple of hundred gas-electric and diesel-electric step vans working routes in North American cities.

Medium- and heavy-duty trucks are the last to become hybridized, but the race is on. All major manufacturers are currently ramping up research and actively testing prototypes. In June, the Volvo Group (world’s biggest manufacturer of Class 8 trucks) announced it was partnering with the US and Swedish governments in an environmental initiative to develop environmentally friendly vehicle technologies, including hybrids.

Volvo seems well-situated to do so, since it has been experimenting with diesel-electric hybrids on both sides of the Atlantic for several years. Volvo’s sister company Mack is developing Class 8 vocational trucks for the US Air Force, including one tanker and two dump trucks.

Other manufacturers, like PACCAR, International and Freightliner, have announced partnerships with powertrain providers like ArvinMeritor and Eaton, and are in the process of evolving their own diesel-electric medium- and heavy-duty truck packages.

Simply put, a hybrid vehicle uses two sources of power. This is usually a gasoline or diesel engine combined with an electric motor and generator. Electrical energy is captured each time the brakes are applied (regenerative braking) and stored in batteries where it can be drawn on to assist the internal combustion engine during acceleration and/or can power a vehicle’s accessories while stopped.

Hybrid vehicle systems operate either in series or parallel configurations. In series, the electrical motor cannot be decoupled from the drivetrain and complements the performance of the gas or diesel engine. In the parallel application, the electric motor can run separately from the other power source, or can be blended to operate in tandem with the IC engine.

Rapidly evolving battery technology is creating more efficient, robust and lighter weight electrical storage systems. The traditional lead acid battery is heavy and provides relatively low kilowatt hour output per weight. Nickel Metal Hydrite batteries, on the other hand, are much lighter and have shown good results in many hybrid applications. Other electrical storage technologies on the horizon include lithium ion batteries (like those used in cellphones) and ultra-capacitors, which both show great promise.

Urban delivery a perfect fit

Hybrid automobiles flipped mileage stickers on their heads. For the first time, city driving became more economical than highway use. Among hybrids, fuel mileage gets better when the brakes are used. The frequent stops and starts of urban delivery step vans make them perfect candidates for hybridization.

Until now, it’s been only the biggest parcel carriers who can afford to experiment with hybrid vehicles. After several years testing designs, Purolator Courier Ltd. now has 49 hybrid trucks deployed across Canada, the majority in Toronto and Vancouver.

“We were pleasantly surprised at the fuel savings,” says Serge Viola, national fleet manager at Purolator. He cites up to 40% less fuel consumption on his first 19 diesel-electric series hybrids, and about 32% savings on the 30 latest gas-electric series step vans. He also figures on spending 20% less on maintenance costs, primarily brakes.

Viola’s next 105 hybrids will be parallel system gas-electrics, to be delivered in the last quarter of 2008. They are expected to get even better mileage since they will be equipped with smaller block gasoline engines, an option that’s currently unavailable from the manufacturer.

Still, the vehicles are expensive (50% higher price tag than conventional trucks) and Viola admits he’s been hard-pressed at times to make the case for hybrids to his company’s board of directors. According to Viola, these trucks won’t pay for themselves until the fourth or fifth year of operation, while most businesses expect a payback on equipment within two or three years.

“It’s nice to have the support and the resources. I’ve sold it on the environment and cost and the vision of where this company wants to be in the future. With almost 4,000 power units, someone’s got to be the guinea pig,” says Viola.

Purolator is also teamed with Unicell and ArvinMeritor to build an all-electric truck called the QuickSider, featuring a radically redesigned cargo area. The QuickSider plugs in at night and produces zero emissions. The prototype has passed Transport Canada testing and will serve Toronto’s downtown core this fall.

Not to be outdone, FedEx prides itself with having the largest hybrid delivery truck fleet in North America with 93 diesel-electric Opti-Fleet E700 trucks, five of them working in Toronto. In May it signed a deal with Azure Dynamics of Toronto for the development of a gas-electric parallel hybrid to be constructed on a Ford E450 chassis. FedEx has committed to buying 20 of the vehicles at the end of the development project.

UPS also has hybrid trucks on the road, but is more interested in a multi-pronged approach. “We have more than 1,500 alternative fueled vehicles in our fleet including hybrid-electrics, propane, natural gas and one hydraulic hybrid,” according to UPS spokesperson Elizabeth Rasberry.

“We’re testing different technologies and are committed to having alternative fueled vehicles playing a part,” adds Rasberry. “Our long term plan is to minimize dependency on fossil fuels by developing a wide variety of technologies.”

Refuse trucks ready to go hybrid

The market for heavy hybrid trucks barely exists, but the interest is great. Most projects are in the advanced engineering state; some are just starting to be rolled out.

“We’re looking at vocational applications for our diesel electric hybrids as our primary focus, particularly refuse trucks,” says Emile Charest, North American Volvo’s hybrid powertrain projects manager.

This seems a good fit, since a large percentage of the heavy refuse trucks in North America are indeed Macks. Sanitary fleets are extremely attractive for hybrid applications. Where a step van may make 100 stops a day, refuse trucks, rear and side loaders, use their brakes even more frequently. Charest’s expects the transition for drivers of Mack’s hybrid refuse trucks to be seamless when it happens.

Volvo’s position is unique in that it supplies its own engines and powertrains, unlike other OEMs who work with partners. “We have some proprietary technology and the controls are proprietary. For the electric motor and energy storage we’re looking at some form of partnering with other providers,” says Charest.

“Mack’s plans are to be in preproduction in late 2009 in the US and Europe,” he adds. “Our diesel-electric hybrids are a global platform, so there will be an application for Mack worldwide.”

Wal-Mart testing hybrid highway trucks

Class 8 highway trucks are perhaps the last to be adapted as hybrids because they don’t brake as much as vocational trucks. There are, however, several initiatives underway looking at highway applications for hybrids and Wal-Mart is involved in two of them.

In January, Wal-Mart announced an agreement with ArvinMeritor to develop a dual-mode diesel-electric hybrid using an International ProStar tractor. Cummins is providing the engine,
controls and motors.

The dual mode diesel-electric drive trains will use blended power from both the mechanical and electric propulsion systems. The electric motor will kick in mostly during low-speed, high-load conditions, but can also provide extra power during hill climbing, even at highway speeds. The mechanical drive blends with the electric motor until the vehicle reaches highway speed where it becomes entirely mechanical. Wal-Mart also has another highway tractor hybrid project on the go with Peterbilt and Eaton Corp. One Peterbilt 386 model tractor, equipped with a parallel type “direct” electric system, is currently being tested, and the manufacturer expects fuel savings of 5-7%.

The 386’s batteries power the heating, air conditioning and electrical systems while the engine is turned off. The diesel automatically starts when the batteries need charging which takes about five minutes per hour. According to Peterbilt, “the proprietary feature minimizes engine vibration during start up and shutdown during the recharge periods, allowing the driver to rest without interruption.”

Back in 2004, the Hybrid Truck Users Forum chose Eaton and International Truck and Engine Corp. to develop 24 advanced pre-production diesel-electric hybrid bucket trucks. The trucks are presently being tested by 14 utilities across North America, among them Hydro Quebec.

Preliminary reports indicate that the vehicles can save fuel by up to 60% and allow the operator to run the cherry picker on-site without idling for 1.5-2 hours. The trucks use lithium ion batteries and also promise reduced maintenance costs.

International is just completing a vigorous round of validation and is expected to have hybrid packages available to customers in 2008 on Class 6 and 7 chassis. “This has gone from an experimental product to a commercially available product run down a high speed assembly line,” says Jim Williams, International’s director of sales and distribution for new products. “Hybrid will be a regular option for our medium product line.”

Eaton is also planning on making its hybrid powertrain option available to Freightliner, Kenworth and Peterbilt customers buying medium- duty trucks next year.

Hydraulic hybrids coming soon

Even more exciting is the hydraulic hybrid that Eaton is proposing. It’s presently conducting trials on hybrid hydraulic power systems, both series and parallel. Hydraulic powered machinery is used worldwide in heavy equipment applications, and the technology is expected to be extremely cost-efficient.

An Eaton-driven series hydraulic hybrid delivery van built for UPS, in conjunction with International Truck and Engine Corp. and the US Army, is getting great results while being road-tested in downtown Detroit. Its unique hydraulic propulsion system stores energy from braking using pumps and compressed nitrogen. It was getting 60-70% better fuel economy in the lab, and apparently similar results in the real world.

Eaton is also developing a parallel hydraulic hybrid system known as the Hydraulic Launch Assist (HLA). The operator can choose either the economy mode with limited maximum torque, or the productivity mode which uses hydraulic power to get the work done faster. Again, refuse trucks seem to lend themselves to hybrid adaptation. One advantage to the hydraulic brake regeneration system is that it can be installed along with the original powertrain without having to modify much of the existing vehicle.

Brad Bohlmann, business development manager for Eaton Corp. Fluid Power Division, expects to have 12 HLA hydraulic hybrids operating in Texas by early 2008. The vehicles will sit on a Class 8 Peterbilt 320 chassis. “We’ve been doing a lot of testing and validation,” he says.

MORE TO READ

More “green” technology trucks were unveiled just as this special supplement was going to press, including developments from Volvo and Purolator. See the Green to Gold section of our next issue or the upcoming editions of sister publications Truck News and Truck West for all the details.

Harry Rudolfs is the rare combination of a journalist and trucker. He has logged more than a million miles, and this insight allows him to tackle the issues truckers love to talk about-and, occasionally, a few they don’t.