Electric refrigeration units: an effective way to start decarbonizing

Refrigerated trailers have recently attracted a great deal of technological interest. Temperature management during the transport of sensitive goods is a crucial issue for companies, especially with increasingly stringent health and safety regulations. Significant risks exist if this management is not precise and reliable, but fortunately, manufacturers are making increasingly high-performance tools available to guarantee this reliability.

The North American Council for Freight Efficiency (NACFE) has published a comprehensive report on low-carbon refrigeration unit technologies. It's a fascinating overview of current technological solutions, and it's not just about refrigeration: innovations like electric power take-offs (ePTOs) are also paving the way for new ways of operating.

Current refrigeration units

Today's refrigeration units, known as TRUs (Transport Refrigeration Units), generally use a diesel-powered internal combustion engine. This engine drives a compressor which maintains a stable temperature in the trailer through a compression-vaporization cycle. Although TRUs are reliable and widely used, they produce significant greenhouse gas (GHG) emissions and generate noise pollution, particularly in urban areas.

Technologies available for TRU

With a view to reducing emissions and modernizing the sector, several technologies are currently available or under development for TRUs:

1. Electric refrigeration units (eTRUs):

• eTRUs operate with electric motors powered by batteries. They reduce greenhouse gas emissions and noise, while ensuring efficient temperature management. They can be powered by traction batteries, dedicated trailer batteries orshore power systems, where the unit is connected to an external source when parked.

2. Hybrid configurations:

• Some TRUs combine a diesel engine for long-distance journeys with an electric option for when the vehicle is stationary. This reduces emissions while maintaining extended range.

3. Generator axles (eAxles):

• This innovative technology recovers the kinetic energy generated by the vehicle's movement to recharge the eTRUs' batteries, thus extending their range without the need for an external connection. However, I remain cautious about the long-term savings. By adding a generator axle, we increase the coefficient of resistance, resulting in higher fuel consumption during recharging. Will we then achieve the savings and reduction in GHGs we had hoped for? That's the question I'm asking myself.

4. Hydrogen refrigeration:

• Although less common, this solution uses hydrogen fuel cells to power TRUs. However, the lack of hydrogen infrastructure limits its widespread adoption.

5. Cold plates and solar panels:

• Cold plates are frozen overnight, maintaining the temperature throughout the day without the need for a motor. In addition, solar panels can be installed on trailers to recharge batteries or power the eTRU directly.

Benefits and challenges of eTRUs

eTRUs offer a number of advantages:

• Lower emissions: By replacing diesel engines, eTRUs help reduce CO2 emissions and improve air quality.
• Less noise: Electric motors are much quieter than combustion engines, which is particularly beneficial for deliveries in urban areas.
• Fuel savings: Thanks toshore power, eTRUs can operate without consuming diesel fuel when parked.

However, certain challenges remain:

• High initial cost: The acquisition of eTRUs is more expensive than that of traditional diesel units, which may slow down their adoption.
• Recharging infrastructure: Companies need suitable infrastructure to recharge eTRUs in their depots or charging zones.
• Battery autonomy: Long journeys can be limited by battery autonomy, although technologies such as generating axles help to mitigate this problem.

ePTO technology: an additional advantage

Another promising development is electric power take-offs (ePTOs), which enable auxiliary equipment such as eTRUs to be powered directly from the vehicle's battery. ePTOs are not limited to refrigeration units; they can also be used for bucket trucks, tankers or other vehicles requiring PTOs. By eliminating the need to run the engine to power such equipment, ePTOs reduce not only fuel consumption, but also mechanical wear and tear, thereby cutting maintenance costs.

conclusion

eTRUs and other available technologies represent a necessary evolution in the refrigerated transport sector, helping to reduce GHG emissions and improve energy efficiency. Although obstacles such as initial cost and lack of recharging infrastructure remain, the long-term benefits, particularly in terms of reduced operating costs and compliance with environmental regulations, make them a promising solution.

These innovations, combined with technologies such as ePTO, enable transport companies to begin their transition to a more sustainable future, while optimizing their operations and reducing their carbon footprint.