A refrigerated trailer powered by batteries and rooftop solar panels has undergone testing in Australia. This innovative technology could radically change the quality and operating cost of the so-called cold chain, a system for transporting food, medicine and other goods that require constant refrigeration.
The tests were conducted by Australia’s Protran Solutions. The testers used a Sunswap Endurance refrigerated trailer, which was developed by the British company Sunswap. During the trip, the refrigeration unit was powered solely by the trailer’s internal batteries and the solar panels mounted on its roof, without drawing power from a diesel generator, the tractor or an external power grid.
As a rule, refrigerated trailers get equipped with a separate diesel engine. It runs continuously during transport, powering the refrigeration unit and maintaining the temperature required for food or medicine. This entails additional costs for fuel, equipment maintenance and carbon dioxide emissions.
In the new system, the diesel engine was replaced by batteries. The refrigeration unit was supposed to draw power from the batteries, which would get recharged by solar panels while the truck was moving or parked. This way, some of the energy would come directly from the sun, and the rest would be drawn from the batteries.
In order to test this hypothesis, a long-distance test run was conducted between Sydney and Brisbane. A semi-trailer with a refrigeration unit completed a round-trip journey of 1,671 km. For about 32 hours, the system maintained precise temperature conditions for both chilled and frozen cargo.
During the trip, the system consumed some 85.9 kWh of energy. Of that amount, roughly 72% (58.9 kWh) was generated by solar panels mounted on the semi-trailer’s roof. Only about 27 kWh, or some 28% of the battery capacity, was drawn from the batteries. Thanks to constant solar charging, the batteries barely discharged: by the end of the trip, about 62% of their energy reserve was left.
According to Protran Solutions, the use of solar energy made it possible to avoid the combustion of about 64 liters of diesel fuel and prevent the emission of some 172 kg of CO₂.
Sunswap claims that the trailer can operate for up to 24 hours in the deep-freeze mode on a single charge, maintaining temperatures from –25°C to ambient temperature. The batteries can also be recharged from the grid, including at night in warehouse conditions.
The developers note that, in addition to producing zero emissions, these systems can reduce operating costs for refrigerated transportation by up to 81%. If widely adopted, this technology could mark a real breakthrough in refrigerated cargo logistics.
