The continuing evolution of alternative transportation fuels, combined with new hybrid motive power and refrigeration system alternatives, reinforces the idea that there is no one best answer.

However, not unlike the continuous evolution in consumer electronics and computers, it appears there may soon be a continuous string of better fuel economics and power source alternatives coming around the corner for years to come. 

Exxon is now devoting large dollar investments into the process of growing and converting algae into a virtually unlimited source of fuel in the not too distant future. Others are making the large investments necessary to develop new catalysts that will make it possible to produce transportation fuels from non-food or feed sources by using renewable and more economical sources like switch grasses, corn stalks and wood chips. Now we’re seeing this happening with cold-plate refrigeration systems, of all things.

A hybrid is defined as “something of mixed origin or make up,” and that’s what is currently beginning to be done with the introduction of hybrid cold-plate refrigeration systems for milk and ice cream route trucks. These hybrid cold-plate systems are designed to be an improved and “greener” alternative to over-the-road mechanical route truck refrigeration systems of the past.

Continuous over-the-road recharge of cold plates using on-board power sources, such as belt-driven power from the truck engine, PTOs or separate gasoline- or diesel-powered generator sets, is not new. But those systems were generally the exceptions to the more common overnight shore power recharge of cold plates only, which was the norm for the industry.

However, in late 2007, that began to change as Johnson and Kidron each introduced what I believe were the first dairy industry route truck “hybrid” over-the-road cold-plate systems. Either of these systems can operate with a conventional- or hybrid-powered chassis. Since then, the “big three” dairy and ice cream body builders have continued to accelerate development of additional delivery route cold-plate hybrid alternatives to OTR mechanical refrigeration.

Kidron’s “UltraTemp” was developed with the help of Azure Dynamics Corp. and uses its low-emission electric power, or LEEP, hybrid system. A truck engine power takeoff turns an electric generator providing power for continuous cold-plate charging while the truck engine is in operation. The system also stores excess electrical power which then provides continuing silent plate recharge while making deliveries. A unique aspect of the LEEP technology permits the ready use of 220 volt three-phase or single-phase plug-in shore power for overnight full recharging.

Johnson’s “RouteMax” OTR cold-plate system was developed in partnership with International Trucks. This system also uses a truck engine PTO to turn a generator providing electrical power to International’s proprietary “Power Pak.” This unit provides both electrical power to charge the cold plates over the road and while the route truck engine is shut down during delivery.

In 2009, Johnson also introduced its “ElectriMax” over-the-road cold-plate system. I see this as a further refinement of the “RouteMax,” which was an exclusive joint product venture with International. As I understand it, ElectriMax still requires a PTO-ready truck chassis to power an electrical generator, but unlike RouteMax, the electrical battery, or power pack, providing power to the cold-plate refrigeration system is not restricted to any particular chassis manufacturer.

In March of this year, Hercules announced the newest, and I believe the most advanced, hybrid cold-plate system yet, working with Eaton Corp., the U.S. leader in the development of proprietary commercial vehicle hybrid motive power systems and hybrid power sources for chassis-mounted equipment. The Eaton/Hercules OTR cold-plate system is possibly the first hybrid-plus-hybrid-refrigeration application. Unlike other OTR cold-plate systems, this does not require the use of PTOs, generators or electrical voltage converters. “Exportable” 208-volt electric power comes directly from the vehicle’s hybrid motive system to operate the OTR cold-plate system while traveling and when the chassis is shut down while making deliveries.

It’s amazing to think that a refrigeration system that was probably put into general use just after World War II is now a leading-edge adaptor to the demands of low carbon footprints and zero emissions.