Back in 2005 several test programs were initiated which introduced hybrid diesel-electric power trains into the bucket truck industry. One of these feasibility studies hoped to determine, specifically, the viability of switching over to a more environmentally friendly way to power forestry trucks and bucket trucks used by utility companies. At that time the hybrid revolution had just begun with passenger cars and light-trucks. But the question that needed answering was could a hybrid diesel-electric engine generate the horsepower and, in turn, the power necessary to operate a bucket truck on the road as well as at the job.

The hybrid bucket truck evaluated in these tests utilized a conventional internal combustion diesel engine combined with an electric motor powered by batteries. It is true that in simple tests, hybrid engines scored higher marks for fuel efficiency. Estimates done by the Eaton Corporation showed that as little as 10,000 diesel-electric hybrid trucks could reduce fuel usage by 7.2 million gallons per year. But would the hybrid system work under adverse conditions at a variety of job sites. When the tests were concluded, the survey proved that the operation of these hybrid engines created fuel efficiency and in some cases, a significant reduction in noise pollution.

One of the biggest savings associated with these hybrid bucket trucks came after the truck was on the job. With traditional bucket trucks, the engine remains running in order to power the bucket's hydraulic lift. It is a different story with the hybrid. Instead of relying on the truck's engine power the lift, the hybrid's transmission substituted a Power Take-Off feature designed right into the vehicle's power train. By using this PTO feature, the bucket truck's engine can be shut off while the bucket is in use. The bucket can be moved at will until the power has been drained to a prescribed point, then the transmission automatically turns the truck's engine back on to recharge the batteries. And all of this is accomplished without any loss of hydraulics to the lift.

An unexpected bonus came in the added degree of safety that was discovered with overall quieter operations. When the engine was turned off, the work crew was better able to hear commands and action requests.

And although these hybrid bucket trucks test trials were successful, the real test comes in commercialization. It will not be easy to juggle the expense of replacing existing fleet vehicles with these new, fuel-efficient, environmentally beneficial bucket trucks. Government and military concerns may be forced to make the switch through legislative mandates, but private companies will have to wait for production of these hybrids to move into high gear before the prices become justifiable to the private sector.

In the meantime the question remains as to whether is it possible to modify or replace existing power trains to transform traditional diesel engines into full-featured hybrids. Companies like I-80, which specialize in the sale of new and used medium to heavy-duty trucks, put their inventory through extensive reconditioning before making them available for sale. A 2008 government committee study on hybrid technologies for medium to heavy-duty commercial trucks concluded that with certain trucks it was possible for a hybrid drive system to be installed by another entity during an intermediate or final stage of the manufacturing process as a retro-fit. But whether or not retrofitting is applicable to the bucket truck industry has yet to be determined.