THE NUMBERS make a compelling argument. Hybrid trailer refrigeration units can reduce operating costs by as much as 70% when compared to traditional diesel-fueled refrigeration, and the savings should grow as electric shore power becomes available at more locations where loaded trailers are parked for an extended time.

Recently, managers at Maines Paper & Food Service, Conklin, New York, reported that 33 trailers with Carrier Transicold’s hybrid refrigeration units have generated nearly $300,000 in annual fuel savings since being placed in service. These trailers are just 6% of the company’s 500-plus trailer fleet.

At Mile Hi Foods Company in Commerce City, Colorado, fleet managers estimated that 27 trailers with Carrier Vector refrigeration units saved the foodservice distributor approximately $85,000 in fuel expenditures during the first year the units were in operation.

Witte Bros in Troy, Missouri, is another refrigerated fleet that is reaping significant savings with Carrier’s hybrid refrigeration units. Managers say fuel savings for the company’s 245-plus refrigerated trailers could be as high as $20,000 a week if they could plug into shore power systems every time a trailer is parked.

Growing popularity

David Kiefer, director of marketing and product management for Carrier Transicold, says these testimonials are hardly out of the ordinary. “It’s because the use of electric standby significantly reduces operating costs—usually 40% to 70% compared to operating on diesel, depending on the cost of fuel and electricity,” he says. “Standby operation brings additional benefits, eliminating emissions and noise from the refrigeration unit engine, while also conserving fuel for the highway. Depending on the fleet and its distribution network, the time a trailer is parked for loading and unloading can account for a large portion of the refrigeration unit runtime, so the savings can be significant.”

Kiefer adds that Carrier has seen a steady rise in demand for the Vector units. “Initial customer demand was piqued by benefits of unit efficiencies, reduced maintenance requirements, and quieter operation offered by electric refrigeration systems,” he says. “The built-in electric standby capability has become a more important feature as fuel prices have risen and customers have recognized the savings potential. In some of the more developed countries in Europe, where hybrid systems have been available longer and fuel prices are significantly higher, more than 70% of the truck refrigeration units sold today have electric standby.”

Carrier’s Vector lineup includes three units, the newest being the 8500 that was introduced in September. The product line includes the 6500 trailer unit, 6600MT multi-temperature unit, and 5100 for stationary applications.

With the Vector 8500, Carrier introduces the first fully hermetic electric scroll compressor used in a North American trailer refrigeration unit, according to Kiefer. The scroll compressor has 70% fewer moving parts and is 200 pounds lighter than traditional reciprocating compressors.

The 8500 comes with Carrier Transicold’s ecoFORWARD technologies that boost performance while providing compliance with the Environmental Protection Agency’s 2013 Tier 4 emissions requirements. “While Carrier’s legacy Vector units are highly efficient, the new ultra-efficient 8500 achieves 5% to 30% more Btus of cooling per gallon of fuel at AHRI rating conditions,” Kiefer says.

The Vector platform’s signature E-Drive all-electric refrigeration technology means refrigeration and heating operations are 100% electric, powered over-the-road by an on-board generator driven by the unit’s diesel engine. Electric standby capability is built in, allowing truck fleets to tap into electric power supplied to run the system when parked.

Using 20% less power than previous Carrier models, the 8500 unit’s 2.2-liter diesel engine is certified for “evergreen” compliance with the EPA Tier 4 standard for engines less than 25 horsepower. For fleets operating in California beyond seven years, the Vector platform’s standard electric standby capability provides an in-use compliance option for the California Air Resources Board (CARB). Carrier Transicold also is developing an optional system that further reduces engine emissions and provides a future CARB in-use compliance Verified Diesel Emissions Control strategy.

Electrified infrastructure

The three fleets described at the beginning of this story have moved aggressively to install the electric standby infrastructure at the distribution center, warehouse, and fleet terminal locations their companies operate. The 460-volt three-phase power stations can cost upwards of $6,000 per unit, and a facility probably will need multiple stations. Each power station can have multiple outlets, though.

That may be enough for refrigerated fleets operating locally or in relatively short hauls. The same can’t be said for longhaul operations. Shore power electric systems are still few and far between at trucks stops and other locations where refrigerated haulers are likely to stop during longer trips.

However, Shorepower Technologies is working hard to address that shortfall. Formed to develop and deploy Electrified Parking Space units at various locations, Shorepower Technologies currently systems in place at about 70 truck stops across the United States, and the company goal is the reach 250. Twenty-nine locations have electric transport refrigeration unit (eTRU) connections.

“The infrastructure is slowly making its way across the country, as we put in eTRU 460-volt connections, along with 120-volt power for cab conveniences,” says Alan Bates, vice-president of marketing for Shorepower Technologies. “But what will transform the concept to widespread reality is more reefer fleets stepping forward for the power, and then detailing where they want it. At $2 per hour for electric power, a refrigerated trailer could save approximately 50% on energy costs versus diesel, not to mention maintenance savings. It is a very straight forward technology and benefit.

“We have the I-5 corridor on the West Coast well connected with eight locations, five of which also have eTRU plug-ins. There are more to come. We just need flagship, large reefer fleets to work with us to zero in on what’s next. I firmly believe that someday many reefer fleets will be able to conveniently enjoy the cold silence of plug-in electric power at truck stops and most everywhere they travel.

“One reason it will take time to build out the eTRU infrastructure is that demand for the system at truck stops is still low. A relatively small number of fleets are running hybrid refrigeration units, and most of those are in local use. To encourage more use of these systems, Shorepower Technologies is putting together a leasing package that bundles the refrigeration unit, trailer, and electric plug-in system for facilities.

“We see indications that hybrid refrigeration units will become more cost competitive in 2014. We think hybrid TRU prices will move closer to diesel units. The hybrid trailer unit population could reach 15% to 20% of the total refrigeration unit population over the next 10 years.”

Kiefer says he also is a true believer of in truck stop electrification, and offering plug-ins for truck refrigeration units will be good for all in the industry. “Everyone wins,” he says. “We anticipate continued growth in the market as people try out hybrid refrigeration units and experience the benefits and performance they provide. As plug-ins become more widely available on the road, it will only accelerate the rate of adoption for hybrids.”