Protran Solutions has completed what it describes as the world’s longest zero-emission, solar-charged refrigerated transport trial, covering 1,671 kilometres between Sydney and Brisbane in a return B-double configuration .
The trial, conducted with Sunswap’s Endurance system, involved a tag, 22-pallet trailer operating entirely on battery-electric refrigeration powered by solar energy. According to Protran, the system maintained temperature control for chilled eggs (+11°C) and frozen meat (-2°C) over 32 hours of continuous operation without drawing power from the truck, trailer systems, shore power or the electricity grid .
Energy use for the journey totalled 85.9kWh, with 27kWh supplied by the battery and 58.9kWh generated by solar. Protran reported that 64 litres of diesel were conserved and 172kg of CO₂ emissions avoided over the course of the trial, with 62 per cent battery capacity remaining at completion .
Importantly, the system operated for seven hours overnight and in the early morning without solar input, including during wet weather conditions, demonstrating battery resilience under less-than-ideal generation circumstances .
Grant Turner, General Manager of Protran Solutions, said the field testing validated depot-to-depot cold chain capability using solar-powered refrigeration.
“These field-testing results have proven what we wanted to validate in terms of cold chain capabilities for solar-powered refrigerated transport for depot-to-depot operations. The Sunswap Endurance system has proven it can handle the Sydney-Brisbane return route while maintaining precise temperature control for frozen and chilled freight types, all without consuming a single drop of diesel for refrigeration,” Turner said .
Turner also pointed to the system’s overnight performance as a key outcome.
“What’s particularly impressive to our trial partner was the system’s performance during overnight operations when there’s no solar generation and significant parts of the trip had rain as opposed to sun. The battery reserves and energy efficiency meant that the trip completed the entire journey using just 28% which is remarkable,” he said .
The return leg included a 13-hour loaded overnight journey with chilled freight, followed by a 19-hour frozen meat transport, concluding with unloading at 2am . Protran said the trial demonstrates the versatility of battery-electric refrigeration across varying temperature settings and duty cycles.
Protran Solutions is the exclusive Australian distributor for Sunswap battery-electric refrigeration units and provides refrigeration system supply, installation and maintenance services to the local transport sector .
The results will likely be of interest to operators evaluating pathways to reduce diesel consumption and emissions within the refrigerated segment of the heavy vehicle fleet, particularly for regular depot-to-depot routes where predictable duty cycles can support renewable energy integration.
