Electric Trailer Refrigeration Units


Shorepower recently demonstrated an electric trailer refrigeration unit (eTRU) in a commercial application. Diesel-engine-driven trailer refrigeration units (TRUs) have become the standard means for keeping fresh and frozen foods cool in over-the-road transport. These units are reliable and efficient, and are critical to maintaining the high level of quality and safety for food and medicines in our national cold chain. However, the engines that power these units create noise and air pollution while the units are running on diesel power. With the rapid rise of diesel fuel prices in recent months, the cost of running these units has increased.

As an alterative to using a diesel engine full-time, an eTRU can be powered by either an on-board diesel generator or a shore power grid connection. The eTRUs used in this project are manufactured by Carrier Transicold and use electric components that allow them to be plugged in when parked. While these units are connected to shore power, diesel usage is eliminated completely thereby reducing fuel costs and the related diesel emissions. Versions of these units have been available in Europe for the past several years, so the technology is well proven. In addition to reduced diesel consumption, these designs offer higher inherent reliability, smaller quantities of refrigerant charge, and much lower potential for refrigerant leakage due to their closed refrigeration system design (similar to household refrigeration). However, eTRUs built to U.S. specifications had not previously been produced due to several market penetration barriers primarily, higher initial costs and the lack of an energy supply infrastructure in the United States to run these units on standby power for a significant portion of their operation time.

To overcome these barriers, Shorepower assembled a team of experts to demonstrate a pre-commercial version of a U.S.-spec eTRU. A technology demonstration project involving ten eTRU-fitted trailers operating at a commercial facility with electrified loading docks was used to demonstrate and collect real-world data on the fuel and emissions impact of these pre-commercial eTRUs. After a successful demonstration of this technology, the TRU manufacturer, Carrier Transicold decided to go forward with an eTRU designed specifically for the U.S. market. The rollout of this technology will be affected by market acceptance that is now strongly driven by diesel fuel prices and turnover of the trailer fleet.

A second electrified facility is now being used to demonstrate this newly released eTRU technology. The eTRU-equipped trailers at the facility will be pulled by shore-power-ready sleeper cab tractors, which will be powered by an under-trailer wiring system connected to the facilitys electrical infrastructure, which was recently patented by Shorepower. This demonstration will enable team members to determine the fuel and emissions impact of installing the electric TRUs by obtaining real-world data. These data can be valuable in modeling emission reductions and it is expected, and will be proven out in this project, that eTRUs, when connected to grid-power, can significantly reduce criteria air emissions, especially in areas where TRUs operate and load cargo.


Download Shorepower’s report to the New York State Energy Research and Development Authority (NYSERDA and read the press release). We are now conducting ongoing work in New York State to equip commercial food warehouse facilities with Shorepower equipment so that eTRUs can be deployed.

Read some e-TRU Electric Standby Case Studies and Articles here:

Related Documents:

Electric Powered Trailer Refrigeration Unit Market Study and Technical Assessment
Electric-Powered Trailer Refrigeration Demonstration
Real-World Demonstration of Grid-Powered Electric Trailer Refrigeration Unit Technology
eTRU Refrigerated Warehouse Technology Demonstrations
DOE eTRU Infrastructure Report
Electric-Powered Trailer Refrigeration Unit Safety Integration Demonstration

Read Other Stories About this Project:

Carrier Transicold Niagara eTRU
Green Car Congress