By Beto Dantas, ConMet’s Chief Technology & Innovation Officer

Across the commercial vehicle industry, tightening regulations and an increased focus on Corporate Social Responsibility are driving fleets toward electrification. Many fleets have been investing in electric technology for light duty last mile delivery and Class 8 tractors. Though these applications are crucial to creating a more sustainable industry, there is ample, largely untapped opportunity to electrify other functionalities. It is time for the industry to address another culprit of urban emissions: Transport Refrigeration Units (TRUs).

Today, most TRUs are powered by internal combustion engines that use diesel fuel. The TRUs emit greenhouse gases and noise when on the road and while idling to maintain the proper temperatures inside the unit. They are even sometimes used as overflow storage for distribution centers and grocery stores when their cold storage runs low during major holidays and events. When this happens, TRUs could run for up to six weeks. Though they are a major contributor to pollution, they are necessary components of the cold chain, critical for the safe transport of groceries, chemicals, medicines, blood, and other products that must maintain stable temperatures.

The race to decrease TRU emissions

The California Air Resource Board (CARB) is poised to enact a new set of regulations on TRU emissions, with ultra-low-emission requirements on TRUs by 2023, and zero-emission requirements as early as 2025. The regulations will apply to any TRU that is sold or operated in the state, regardless of where they are based. As California is often a leader in emissions regulations, more states are expected to impose similar regulations in the coming years. In fact, just last year, 15 states plus the District of Columbia announced an initiative to work together to ensure that 100 percent of all new medium- and heavy-duty vehicle sales be zero-emission vehicles by 2050.

Regulations are not the only force behind the electrification of TRUs. Large fleets are also setting ambitious Corporate Social Responsibility goals to drastically lower their emissions, often in a shorter timeframe than regulations dictate.

So why isn’t the electrification of TRUs further along by now? The concern of an electric TRU is similar to the concern of any electrified vehicle: operating time. TRUs require large amounts of energy, which often translates to large, heavy batteries and frequent charging needs. However, there is an alternative approach.

Creating a Zero-Emission Trailer

ConMet eMobility’s Preset Plus® eHub repurposes energy from coasting and braking to provide auxiliary power and propulsion assist in a lightweight package, creating a zero-emission trailer.

An in-wheel electric motor within the hub assembly captures energy that would otherwise go wasted as heat from friction brakes. The electricity is stored in a high-capacity battery and then shared with other parts of the vehicle as needed. The stored battery energy powers the electric TRU to keep the trailer cool, and also powers the eHub motors to propel the vehicle forward. Patent-pending controls balance regeneration, auxiliary power use, and propulsion to optimize energy harvesting and ensure the TRU is always keeping valuable cargo cool.

The benefits of the zero-emission trailer are enormous:

Eliminates the need for diesel fuel for the TRU
Improves overall vehicle fuel efficiency
Regenerative power eliminates the need for shore power
Reduces friction brake wear
Allows for access to restricted emission and restricted noise urban zones
Can be paired with an electric tractor for a fully zero-emission vehicle

This lightweight, clean energy solution is ideal for urban routes with several stops, such as grocery delivery, but customization and flexibility make the eHub practical for any reefer application. Power is regenerated anywhere the trailer goes, including city streets, expressways, highways and freeways. Custom controls and variable battery pack sizes are designed to meet the energy needs to specific routes and hauls. 

When a fleet introduces the zero-emission TRU, either through retrofitting or a new build, it is seamlessly integrated into operations. No additional infrastructure is needed thanks to the eHub’s regenerative power, and additionally there is no change to the driver experience. The system is fully automated, and once installed the reefer is immediately powered with clean energy, helping fleets meet or exceed CSR goals and comply with regulations.

ConMet eMobility is committed to providing transformative technologies for an era of alternative power and is proud to offer fleets the opportunity to trial the eHub. Visit to learn more, or contact to schedule your zero-emission trailer experience today.

About ConMet eMobility

ConMet eMobility was established in 2019 to address the needs and challenges of clean energy technology. The growing team has years of experience in electrical engineering, system controls, battery science, and more. Together with the unmatched wheel end expertise and support of ConMet, ConMet eMobility is enabling the development of zero-emission commercial vehicles, capturing and regenerating the kinetic energy that would otherwise go wasted. 

About ConMet 

ConMet, a division of Amsted Industries, is a leading global supplier of wheel hubs, aluminum castings, and structural plastics to original equipment manufacturers and aftermarket channels in the commercial vehicle industry. Founded in 1964, ConMet innovation has been critical in designing, engineering, and manufacturing revolutionary technologies for trucks and trailers. Today, ConMet products are standard equipment on most heavy-duty vehicles in North America and have a growing footprint worldwide.

ConMet is committed to creating products and services that align with critical customer needs. The development of more efficient products, processes, and technology that transform the way customers run and maintain their vehicles is central to ConMet’s vision.