In recent years, the photovoltaic industry has experienced significant growth due to technological innovations that enable the installation of flexible and extremely thin solar panels on the body and roof of vehicles. Their presence not only boosts vehicle range but also enhances battery performance and extends battery life. One particularly interesting application is solar-powered truck refrigeration, which holds great potential in the heavy transport industry where energy autonomy and cost savings are crucial for companies' competitiveness.
Refrigerated trucks count among vehicles with the highest consumption, as they require a continuous power supply to maintain temperatures ranging from 0 to +7° C, and even -18° C for frozen food transport.
Solar panels for refrigerated trucking convert sunlight into electricity during daylight hours. The generated current is then regulated by the Maximum Power Point Tracking (MPPT) converter, which acts as the "intelligence" of the PV system. The converted electricity is stored in batteries, which in turn power the Transport Refrigeration Unit (TRU) of the trailer, ensuring its proper operation.
While these are the fundamental workings of a solar system, there are various configurations available for refrigerated mobility, ranging from hybrid to fully electric solutions.
In the latter case, there are more viable ways to eliminate the diesel generator in favor of an electric and sustainable system.
One way is to combine photovoltaics with the axle for regenerative braking. Yet, equally effective and capable of achieving the same level of autonomy is a system consisting of panels, energy-storage battery and grid-connection capability.
An additional option is to install solar panels on the sides of the trailer and connect them to a suitably sized battery. The choice of configuration depends primarily on the type of travel undertaken by the vehicle.
All logistics companies with fleets of refrigerated vehicles can benefit from the economic and fuel savings resulting from these configurations. The advantages also extend to cases where solar panel-generated electricity supplements a hybrid refrigeration system, thus flanking the diesel engine.
As mentioned at the outset, the battery—as the most expensive component of the electrical system—nevertheless benefits from the presence of photovoltaics which, by preventing deep discharges, extends its life. With a longer-lasting battery, the expenses for replacement are also more diluted over time and within the operating costs to be considered for the heavy vehicle.
Another undoubtedly important factor is that such a unit generates less pollution. The TRUs currently in circulation are for the most part very old and not subject to any emission regulations. Research conducted in 2018 in the UK alone equated the emissions from the refrigeration systems of the 34,000 reefer trucks on the road in the UK with that of 1,800,000 Euro 6 diesel cars (1).
It goes without saying that equipping a cooled trailer with a refrigeration system powered by solar panels is a cost-effective choice on several fronts, even in consideration of the European Union’s directives on sustainability.
When it comes to solar-powered refrigeration for trucking, Solbian flexible solar panels with their Solbianflex technology are among the best choices, due to being made with cells capable of converting over 24% of sunlight into electricity, meaning greater powers can be achieved even in small spaces. This equals truly remarkable value for the type of module.
High performance is not the only strength of Solbianflex technology, which is distinguished by the flexibility and lightness of its products—suffice it to say that the panels weigh less than 2.5 kilograms per square meter compared to the 12 kilograms of traditional aluminum-framed panels.
Thanks to these features and the thickness of less than 2 mm, Solbian flexible solar panels fit perfectly into the context of solar-powered truck refrigeration, being able to adapt to every part of the body and not just the trailer. In addition, the high resistance to weathering (extensively tested in the marine industry) and vehicle vibration renders these panels particularly suitable due to being much less prone to breakage and damage than traditional glass modules.
As stated earlier, the installation of solar energy systems results in significant economic savings — both direct and indirect — that can be seen in reduced fuel consumption and lower maintenance expenses.
The Return on Investment depends on several factors, starting with the degree of customization and configuration of the entire system, including the electronic component, which largely affects the installation price. As such, a technical consultation based on individual needs and the type of vehicle is always necessary.
What we can say with certainty is that in the past decade, photovoltaic production capacities have increased dramatically. Conversely, prices for the technology have declined, providing opportunities for applications that would have been economically unfavorable in the past.
Currently, for a 5 kWp solar system, including charge controllers and accessories, the ROI is about 4 years.
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