Driving Change

5 hot technologies for cold trucking

Dearman, refrigerated truck
Dearman
The chilled nitrogen in Dearman's trucks cools the trailer and also expands as it warms, driving a piston and generating power. So the liquid nitrogen both powers the trailer and provides the cooling.

Since the advent of refrigerated trucks, or "reefers" as the industry calls them, food and transportation have been intricately linked.

Cold trucks cut down dramatically on food waste and provide the backbone for moving perishable food — from tomatoes to tri-tip to tilapia — to stores and consumers. At the same time, refrigerated trucks use a quarter more fuel (usually diesel) than non-refrigerated trucks do, as well as hydrofluorocarbon chemicals for cooling, which are a potent greenhouse gas.

Because of these negative environmental effects, companies that sell and use reefer trucks are beginning to test out ways to reduce the greenhouse gas emissions associated with transporting food that needs to be chilled. Some of these innovations are technologies that can be used on lower-emission trucks in general, but some have been created specifically for refrigerated trucking. 

Here are five hot technologies for cold trucking:

1. Electric, of course: Aligning with the overall trend of vehicles electrifying, some companies have been testing electric refrigerated trucks. Startup Chanje has developed an electric refrigerated van in conjunction with refrigeration giant Thermo King. The companies debuted a prototype of the vehicle at the huge commercial EV show ACT Expo last year (which is coming up in May; we'll be there!)

In Europe, Renault Trucks has developed an electric refrigerated box truck. These electric vehicles can be particularly beneficial in urban environments, where they not only can slash city air pollution but also eliminate the noise associated with delivery trucks in neighborhoods.

2. Trailer-top solar: For larger refrigerated trucks that use a trailer equipped with a separate engine, solar panels on the roof and a battery in the back of the trailer can help. (Truck industry pro tip: The trailer is the back part of the truck that holds stuff). A company called eNow makes a solar-powered cooling unit that replaces the engine of a refrigerated trailer. As our buddy Bill Van Amburg, executive vice president of CALSTART, says in this piece: "Many of the small engines used to power the conventional refrigeration units are essentially unregulated and so are highly polluting."

This is a pretty interesting application for solar in trucking. Other truck makers are starting to explore how to use solar panels to power the auxiliary systems of trucks, used to run air conditioning, heating or TVs for drivers that sleep overnight in the cabs. And just to note, most truck makers are not looking to power a truck with solar panels — the propulsion energy needs of a truck are too high and the real estate on the roof is too low. 

3. Liquid nitrogen: Now this one's cool (awful pun intended). A British company called Dearman has developed an engine that uses liquid nitrogen, which is chilled to negative 320 degrees Fahrenheit. The chilled nitrogen cools the trailer but also expands as it warms, driving a piston and generating power. So the liquid nitrogen both powers the trailer and provides the cooling. 

4. Smarter reefers: The same types of communications technologies — GPS, machine learning, 5G — that are helping connected vehicles reduce fuel consumption also can be applied to reduce fuel consumption of refrigerated vehicles. Researchers suggest that truck operators still need better models for helping them factor refrigerated loads into reducing emissions through routing. But companies are already building "reefer management systems" that use the latest software and sensors to operate much more efficiently. 

5. Advanced thermal materials: Next-generation materials are being tested that can more efficiently heat and cool environments such as the inside of a trailer. In particular, phase change materials absorb and release heat when they go through a change in phase such as from a solid to a liquid (ice melting) and can be used in new ways. If refrigerated trailer makers can find materials that can better maintain cooling during the day for longer, without using the truck's energy-hungry cooling unit, such trailers could lower fuel use for refrigerated trucks. 

This article is adapted from GreenBiz's weekly newsletter, Transport Weekly, running Tuesdays. Subscribe here

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