Sunswap and Protran Solutions have successfully demonstrated a solar-powered refrigerated trailer designed to eliminate diesel dependency in the cold chain industry. By integrating rooftop solar panels with high-capacity batteries, the Sunswap Endurance unit provides a zero-emission alternative to traditional diesel generators. A recent 1,600-kilometer trial across Australia proved the technology’s efficacy in extreme heat, maintaining cargo temperatures without noise or CO2 emissions. This innovation offers a cost-effective, lightweight solution for logistics companies aiming to meet tightening environmental regulations while maintaining operational efficiency.
The logistics industry has long struggled with the environmental impact of refrigerated trailers, commonly known as “reefers.” While the trucks pulling these trailers are increasingly moving toward electrification, the cooling units themselves typically rely on independent diesel-powered generators. These units often run continuously to preserve perishable goods, resulting in significant CO2 emissions and noise pollution in both industrial hubs and residential neighborhoods.
To address this challenge, Sunswap has developed the Endurance system, a fully electric refrigeration unit that utilizes the vast, underused surface area on top of semi-trailers. By installing a series of solar panels across the roof, the system continuously charges onboard batteries. These batteries power a high-efficiency cooling system developed in partnership with Protran Solutions. For added reliability, the system can also be charged via the electrical grid during loading, unloading, or overnight stops.
The technology recently underwent a rigorous real-world assessment in Australia to prove its viability under harsh conditions. The Sunswap Endurance trailer completed a 1,600-kilometer round trip between Brisbane and Sydney over the course of three days. Despite extreme temperatures that usually force diesel units to work at maximum capacity, the solar-powered trailer maintained the required temperatures for meat, milk, and produce while consuming no diesel and producing zero exhaust.
Grant Turner, General Manager of Protran Solutions, noted that the intense Australian sun—traditionally a burden for diesel cooling systems—actually serves as an advantage for this new technology. According to Turner, the equation is flipped: the more the sun shines, the more power is generated exactly when the cooling demand is highest.
Unlike other electric refrigeration attempts that rely on heavy e-axles or regenerative braking systems, the Sunswap approach focuses on simplicity and weight reduction. By avoiding complex mechanical components that add mass and reduce cargo capacity, the solar-and-battery configuration remains economically competitive. As the cost of solar modules and battery storage continues to decline, the financial incentive for fleet operators to switch from diesel is becoming increasingly clear.
Michael Lowe, CEO of Sunswap, emphasized that the Endurance model is already delivering groceries across the United Kingdom, Europe, and South America. The partnership with Protran Solutions marks a significant expansion into the Australian market, offering operators a way to achieve zero-emission transport from the first day of implementation. The Sunswap Endurance unit is scheduled to be featured at the upcoming TruckShowX in Hunter Valley this May, showcasing the future of sustainable heavy transport.