OYSTER BAY, N.Y. -- Despite growing interest in hybrid vehicles, manufacturers have been slow to integrate hybrid technologies into commercial trucks and buses, a study has found.

NextGen Research of Oyster Bay, N.Y, states that some manufacturers consider the efficiency of diesel engines too hard to beat, while others await fuel-cell technologies that can be integrated with commercial drivetrains. Still others are producing and testing concept vehicles they hope will be the cornerstones of commercial hybrid fleets.

The report forecasts the global commercial hybrid vehicle market will triple, from 8,653 units in 2008 to more than 27,000 units in 2013. NextGen Research foresees this market will begin to grow more quickly in 2010, as the global economic downturn ends and the testing of hybrid vehicles in commercial fleets is completed.

Commercial vehicles can't downsize the internal combustion engine to add an electric motor, because trucks, vans and buses need a certain level of power to make it up hills (especially when carrying full loads), and smaller engines would strain to accomplish that.

Already-heavy commercial vehicles would need sizable, heavy battery packs to support an electric motor solution large enough to help propel the vehicle, but that additional weight would place more strain on the motor and the engine, and could reduce cargo capacities.

For the benefits of hybrid technology to be realized, the appropriate type of hybrid technology must be matched to a specific duty cycle.

Larry Fisher, research director of NextGen Research, explains Low-speed stop-start drive cycles are where hybrids are superior to traditional diesels, as those scenarios allow innovations like regenerative braking to recapture much of the energy typically lost when slowing a huge, heavy vehicle.

-- via Truckinginfo.com