PORTLAND, OR – Two first-generation hybrid-diesel trucks are set to go into service later this month in Oregon. Organically Grown Co., the Eugene-based produce distributor, and Portland General Electric are both about to add hybrid trucks to their fleets, according to the Web site www.registerguard.com.

Kenworth and Peterbilt, both owned by Paccar Inc. in Bellevue, Portland-based Freightliner, Mack Trucks Inc., and International Truck and Engine are all testing medium-duty hybrid trucks this year with plans to begin production models soon. They use hybrid-diesel systems that are up to 35 percent more fuel efficient than conventional diesel power plants — a savings that could put a serious dent in the 38 billion gallons of diesel burned each year by the U.S. trucking industry.

Organically Grown will use a medium-duty Kenworth hybrid for in-town deliveries at its Clackamas facility. Organically Grown will lease the truck from Roberts Motor Co., a Portland Kenworth dealer. The company plans to use biodiesel in the hybrid as it does with its other trucks.

The Kenworth hybrid is expected to deliver up to 30-percent greater fuel efficiency compared to a conventional model, according to the company.

Portland General Electric, meanwhile, is about to add an International hybrid rig to its fleet of 142 bucket trucks as a pilot project. The utility is interested in potential cost savings of a hybrid as well as the environmental benefits, according to www.registerguard.com.

Likewise, the Thurston County Public Works Department in Washington state is waiting for its first hybrid-electric truck, a Kenworth equipped with a hydraulic bucket on the back. In addition to getting improved mileage and emitting fewer pollutants than a conventional truck, the electric motor in the hybrid truck is used to power the bucket for up to two hours, which means the diesel engine can be shut off instead of idling while a worker uses the bucket.

Kenworth officials don’t yet have a retail price for the hybrid truck, but Thurston County is paying $73,000 for the chassis — about $1,000 more than what it would pay for a conventional truck. The price reflects a significant discount for being among the first to field-test a hybrid.

Also, Wal-Mart Stores Inc., which operates the nation’s second-largest truck fleet, recently said it was buying a Peterbilt hybrid truck as part of its “Sustainability 360” program to promote environmental stewardship.