Hybrid TRUs offer a versatile solution, capable of operating on diesel during transit and seamlessly switching to electric "shore power" when docked for loading, unloading, or storage. This dual-source capability delivers substantial benefits. For instance, running on shore power drastically reduces noise levels, a crucial advantage for trailers parked in residential areas near grocery stores or distribution centers. Beyond the acoustic benefits, electric operation can slash energy costs by half compared to diesel. Major grocery and food service providers like Kroger, Albertsons, Golden State Foods, and H-E-B are already investing in 480-volt dock plugs to accommodate this shift, highlighting the industry's readiness to embrace these greener options. Utility Trailer, in collaboration with Schmitz Cargobull, offers hybrid TRUs for its 3000R refrigerated trailers, with strong demand particularly from California, where stringent California Air Resources Board (CARB) ultralow emissions standards are a key driver.
Fully electric TRUs, while still facing infrastructure challenges, are demonstrating robust performance and hold immense promise. Companies like PLM Fleet, a leading refrigerated trailer leasing provider, have been integrating electric TRUs into their extensive fleet for over five years. With units incorporating solar, battery pack, and wheel regenerative technologies from various manufacturers, PLM Fleet emphasizes diversification to adapt to evolving technologies. Their experience indicates that electric units closely mimic diesel counterparts in cooling capability, with no significant load loss issues reported. Furthermore, electric TRUs often boast slightly higher uptime due due to fewer maintenance-intensive components.
The compatibility of electric TRUs with emerging electric tractor technology, such as the Tesla Semi's electric power takeoff (ePTO) feature, further strengthens their appeal. This allows electric tractors to directly power refrigerated trailers, paving the way for truly zero-emission cold chain logistics.
Despite the clear advantages, the widespread adoption of hybrid and electric TRUs faces hurdles. Infrastructure remains a primary concern, with limited charging availability at common route stops like truck terminals and distribution centers. This can make consistent access to power difficult and necessitate changes to operational workflows and additional driver training. The added weight of electric TRUs can also impact payload capacity, requiring adjustments in route planning and load strategies. Furthermore, battery health monitoring is critical to ensure reliable operation.
However, the industry is actively addressing these challenges. Telematics systems, such as Utility Trailer's TrailerConnect and Carrier Transicold's Lynx Fleet, are crucial tools for monitoring TRU components, battery health, and operational data, providing fleet managers with vital insights. Manufacturers are also innovating, with companies like Carrier Transicold introducing all-electric, engineless TRUs and power management architectures that maximize energy efficiency. Thermo King has integrated its hybrid and electric TRUs with Range Energy's eTrailer system, which uses an electric axle and high-voltage battery to power refrigeration.
Strategic partnerships with electric utilities and leveraging available grants, particularly in states like California through programs like The Carl Moyer Program and regional air district grants, are vital for overcoming infrastructure limitations. While the transition may take time, requiring meticulous planning, revised standard operating procedures, and comprehensive training for drivers and operational personnel, the long-term benefits of a greener, more efficient refrigerated transport sector are clear, driving continued innovation and investment.
