By now, it’s apparent that hybrid technology is emerging as a significant force in the war on fuel consumption. There now are several players, and probably more to come. Here’s the latest:
ArvinMeritor and Wal-Mart Transportation have agreed to develop a dual-mode, diesel-electric drivetrain for a Class 8 tractor. The vehicle will be based on an International ProStar tractor with a Cummins engine.
ArvinMeritor will provide the tandem axle, regenerative braking system, air disc brakes and advanced ABS with integrated stability control and driver assistance systems.
Wal-Mart has said that, within the next 10 years, it intends to double the fuel efficiency for its fleet of heavy-duty trucks. Dual-mode diesel-electric drivetrains, which have both mechanical and electrical propulsion systems, use the electric motor drive primarily for periods of high demand under low-speed, high-load operating conditions, such as accelerating from a stop. Once moving, the mechanical propulsion system begins to blend its power with the electric motor until it reaches highway speeds, where the drive phases to completely mechanical. The electrical system can provide additional power during hill climbing.
In addition to its work at highway speeds, the engine also charges the batteries. Energy generated during braking also is captured and routed to the batteries.
In other news, the U.S. Environmental Protection Agency recently unveiled a series hydraulic hybrid diesel urban delivery vehicle, a result of a partnership between the EPA, U.S. Army, UPS, International Truck and Engine Corp. and Eaton Corp.
The EPA and UPS plan to evaluate the vehicle’s fuel economy performance and emissions during a series of tests. In laboratory testing, the EPA’s patented hydraulic hybrid diesel technology achieved a 60 to 70 percent improvement in fuel economy and more than a 40 percent reduction in carbon dioxide emissions, compared to a conventional UPS vehicle.
The EPA estimated that when manufactured in high volume, the added costs of the hybrid components could be recouped in less than three years through lower fuel and brake maintenance costs.
In the series hydraulic hybrid diesel, a high-efficiency diesel engine is combined with a hydraulic propulsion system, replacing the conventional drivetrain. The vehicle uses hydraulic pumps and tanks to store energy, similar to what is done with electric motors and batteries in hybrid electric vehicles. Fuel economy is increased by braking energy recovery, and by the diesel engine being shut off when the vehicle is stopped or decelerating.
The diesel hydraulic hybrid truck potentially is eligible to qualify for a tax credit that is up to 40 percent of the incremental cost of the vehicle under a provision of the Energy Policy Act of 2005 for medium- and heavy-duty vehicles.
Also, Eaton has announced that it has begun development of a hybrid electric power system for heavy-duty vehicles, which will be similar in design and will share many of the same components as the company’s medium-duty hybrid electric system built for Class 4-7 vehicles.
Finally, Volvo CEO Leif Johansson and Mack Trucks President Paul Vikner recently unveiled a construction truck from the Volvo Group’s Mack subsidiary, a Mack Granite, which is equipped with a hybrid driveline, which was developed for the U.S. Air Force.
Volvo’s solution was named I-SAM-Integrated Starter Alternator Motor-and reportedly can provide fuel savings of up to 35 percent depending on application. The first vehicles are expected to enter production in 2009. Volvo also is developing hybrid technology for construction equipment, such as wheel loaders, in which the fuel savings, the company says, can be up to 50 percent.
Hey, we’ve only got one Mother Earth, and finite resources. Efforts like these need to be applauded and encouraged.
