Slide Show: Hybrid Trucks Are Here for the Long (Medium and Short) Haul
An explosion in the number and kind of commercially available hybrid trucks means battery power isn't just for lightweight commuter vehicles anymore
ELECTRIC DRILL The Terex Commander 4047 by Dueco, with a hybrid power train by Odyne, is a plug-in electric hybrid with an all-electric mode suitable for low-noise operation on a drilling site. (Most of the noise from a truck of this kind comes from its diesel engine.)
PLUG-IN PROPONENT Andrew Frank [
far left], a professor of mechanical engineering at the University of California, Davis, who is widely credited with inventing the plug-in hybrid vehicle, is currently collaborating with the U.S. Department of Defense to develop a plug-in delivery truck for use on military bases. His ultimate goal, he says, is to power these vehicles from renewable energy generated on-base, such as from arrays of solar panels similar to the ones in this photo. Andrew Frank
BIG (GREEN) RIG The largest trucks on the road, so-called "class 8" trucks, with a gross volume weight of 33,000 pounds (14,950 kilograms), have been among the most challenging vehicles to hybridize, mostly because of the way in which they're used for long hauls on highways: Absent the frequent stops and starts of city traffic, the regenerative braking of a hybrid–electric power train doesn't have many opportunities to recover energy and improve fuel efficiency.
That hasn't stopped discount retail chain Wal-Mart from testing hybrid class 8 trucks, purchased from both Peterbilt and ArvinMeritor. Wal-Mart is currently testing how these rigs operate on a range of fuels, including reclaimed grease fuel from Wal-Mart and Sam's Club stores. As with any new technology, they want to test real-world performance. Wal-Mart
MILITARY APPLICATIONS The U.S. Department of Defense, the world's single largest consumer of liquid fuels, has worked with companies such as Oshkosh Corp. to develop hybrid versions of many of its vehicles. Oshkosh's Heavy Expanded Mobility Tactical Truck with the ProPulse diesel–electric drive system not only saves fuel, it also "serves as an onboard AC electric generator with enough output to power an entire airfield or hospital," according to the company.
PRESIDENTIAL INITIATIVE President Obama stands in front of a plug-in hybrid Ford F-550 "trouble truck" that was jointly developed by the Electronic Power Research Institute, Eaton Corp. and Ford. The vehicle is currently being tested at Southern California Edison, one of over 30 utilities supporting this program. Speaking with Obama is Ted Craver, president, CEO and chairman of Edison International, the utility's parent company.
Electric Power Research Institute
EARLY ADOPTER FedEx was an early adopter of hybrid trucks, and until 2008 could boast that it maintained the largest fleet of hybrid electric vehicles in North America. (That crown was passed to UPS in May 2008, when it ordered 200 hybrid trucks, and then to Coca-Cola Enterprises in January 2009, which boosted its fleet to a total of 327.) FedEx currently maintains a fleet of 170 hybrid trucks that has racked up more than 3.5 million miles (5.6 million kilometers) of service.
ELECTRIC TRUCK Electric Vehicles International makes hybrid–electric and fully electric trucks, and claims to have the first road-ready all-electric truck available in the U.S. EVI takes the somewhat unusual step of leasing rather than selling its users the batteries in its vehicles. Most of the 2,000 trucks it has shipped to date are used in Mexico.
Electric Vehicles International
BUCKET TRUCK Bucket (utility) trucks with hybrid–electric power trains achieve all the efficiencies of conventional hybrids (such as increased fuel efficiency through regenerative braking) and also have a another advantage: the trucks can be turned off when only the bucket lift is being used. This allows up to two hours of continuous lift operation, after which the diesel engine automatically switches on and recharges the vehicle's batteries within five minutes.
Eaton Corporation Advertisement
TAKING OUT THE TRASH Hydraulic hybrid refuse trucks built by Peterbilt, with power trains by Eaton, store energy recovered from braking as compressed hydraulic fluid, rather than electricity. Stored energy can then be used the next time the driver steps on the gas as a "launch assist," which takes some of the load off of the truck's diesel engine when it accelerates from a standstill.
In this image, the hydraulic hybrid system is highlighted in blue. Eaton Corporation
HYBRID FLEET Coca-Cola Enterprises, a bottler and distributor, has the largest fleet of hybrid trucks in the U.S., with a total of 327 trucks. Roughly half the hybrid fleet consists of delivery trucks, which see significant fuel savings (up to 30 percent) when compared with conventional vehicles. That's because they spend a lot of time stopping and starting in traffic, which allows them to take full advantage of regenerative braking charging their batteries.
MILD HYBRID Conventional refrigerated and utility trucks draw power from the diesel engine to power onboard electronics, but it's often more fuel-efficient to power these systems via batteries. (For instance, using stored energy to keep a refrigerated truck cool allows the vehicle's engine to be switched off when the truck is not in motion.)
Azure Dynamics's Low Emission Electric Power System is a "mild hybrid" electric system that provides power for these and other applications. (Mild hybrid means that the system is not part of the vehicle's power train, rather it powers ancillary electronics like a refrigeration system or a lift.) Azure Dynamics Corporation Advertisement