Kenworth recently delivered two prototype Kenworth T680 tractors, each equipped with a series hybrid-electric propulsion system, to Southern California drayage, warehouse and transportation company Total Transportation Systems Inc. (TTSI).
The two T680 day cab tractors – Kenworth’s second-generation range-extended electric trucks – can operate in zero emissions mode on batteries for 30 miles. The batteries can be recharged while driving using an onboard generator powered by a near-zero emissions natural gas engine.
Built under a project funded by California Climate Investments and the Greenhouse Gas Reduction Fund (GGRF) and administered through the California Air Resources Board and South Coast Air Quality Management District, Kenworth Research and Development Director Brian Lindgren said the trucks were developed "to explore and evaluate potential alternatives to diesel power for Class 8 commercial trucks, and to broaden Kenworth’s experience with electrified powertrains."
The two Kenworth T680 hybrid-electric vehicles use the Cummins Westport L9N Near Zero (NZ) emission engine fueled by compressed natural gas (CNG) driving a generator to extend the truck’s battery range. The truck uses lithium-ion batteries to achieve its zero emissions range and to supplement power from the generator when climbing grades.
The system’s energy management and control capabilities ensure that energy generated by the engine and regenerative braking system is appropriately applied through the electric motor, resulting in lower fuel consumption. Recent tests comparing the range extended electric truck to a conventional natural gas powertrain showed a 23% improvement in fuel economy and an 18% reduction in CO2 emissions.