TRU Regulatory Concepts Identified in CARB Sustainable Freight: Pathways to Zero and Near-Zero Emissions

Proposed new rules for transport refrigeration units (TRUs) are described in the California Air Resources Board (CARB) Sustainable Freight: Pathways to Zero and Near-Zero Emissions Discussion Draft document:


Appendix D:

B. Zero Emission Requirements
5. Transport Refrigeration Units

Action Description: Develop and propose a regulatory requirement to prohibit the use of fossil-fueled transport refrigeration units for cold storage in phases, with incentive support for infrastructure.

ARB Action: 2016

ARB Implementation: 2020+

Type of Action: ARB Regulation and Incentive

Overview: Transport refrigeration units are refrigeration systems that are powered by integral internal combustion engines designed to control the environment of temperature-sensitive products that are transported in trucks, trailers, railcars and shipping containers. They may be capable of cooling or heating. Products include, but are not limited to food, pharmaceuticals, plants, medicines, blood, chemicals, photographic film, art work, satellites, and explosives. This regulation would address several transport refrigeration unit uses that result in excessive criteria pollutant and GHG emissions, such as:

  • Use of transport refrigeration unit-equipped trailers at distribution centers and retail delivery points (e.g. grocery stores) for cold storage during the weeks before holidays and major events (e.g. Super Bowl) when the facility runs out of cold storage space.
  • Operation of transport refrigeration units in distribution centers yards and outside the distribution centers gates while waiting for an available loading dock space, for manpower to be available to unload goods, or for dispatch or driver pick-up. Such operations can go on for several days (e.g. load up on Friday for dispatch on Monday).

The initial concepts of the proposed regulation would limit the amount of time that a transport refrigeration system powered by a fossil-fueled internal combustion engine can operate at any facility. The time limit decreases over time.

  • Phase I: 24 hours, effective January 1, 2020
  • Phase II: 1 hours, effective January 1, 2022
  • Phase III: 5 minutes, effective January 1, 2025

Use of zero emission all-electric plug-in transport refrigeration systems, hydrogen fuel cell transport refrigeration, and cryogenic transport refrigeration would be encouraged, as well as adequately-sized cold storage facilities, and more efficient appointment scheduling.

Applicable compliance includes plugging in hybrid-electric TRUs, electric standby TRUs, all-electric refrigerated trailers, and shipping containers into shore power with grid-supplied electricity instead of conventional diesel engine-powered TRUs while parked.