Solar-powered refrigerated trucks are the future of sustainability in trucking.
The high consumption of heavy vehicles and the rising cost of traditional fuels have made investing in solar panel technology a hot topic of conversation in powering cold storage.
Although it may seem like a revolutionary solution, engineers have been studying, applying and monitoring the effect of photovoltaics on vehicles since the late 1990s—with surprising results.
One significant study, with specific reference to solar-powered refrigerated trucks, is that conducted in 1998 (1) by the Sainsbury’s supermarket chain, which showed how the application of photovoltaic modules on the roof of the trailer resulted in a reduction in diesel fuel consumption, showing a Return On Investment (ROI) in about 15 years, even when factoring in the cost of batteries.
A few years later, in 2001, a theoretical study by the U.S.-based Sandia National Laboratories (2) calculated an ROI of approximately 20 years, also taking into account the additional weight associated with the photovoltaic system, which at that time consisted of modules significantly heavier than today's versions.
Nowadays, technology has lowered the costs of PV systems and batteries, bettering the performance and efficiency in power generation, reaching ROIs in less than 4 years, with further improvements expected through mass production of PV panels for vehicles (3).
With data referable to systems made with panels produced by Solbian, we can safely say that in 2023, a 5 kWp solar system (including charge controllers and accessories) has an ROI of 4 years.
The most obvious and tangible benefits that entire fleets of solar-powered refrigerated trucks can offer are reductions in emissions, fuel consumption, and battery-related maintenance costs.
So, why not opt for a complete electrification of vehicles intended for trucking? While electrifying heavy transport would undoubtedly yield a significant reduction in pollutant emissions, the insufficient charging infrastructure for heavy electric vehicles currently poses a barrier to achieving the European Union's targets for 2050. Nonetheless, in this scenario, photovoltaics can be an important contribution to transportation sustainability, thanks to the self-generation of electricity provided by solar panels.
In the case of refrigerated trucks, conventional refrigerated trailers typically utilize single- or multi-temperature cooling technologies to transport both refrigerated products (ranging from 0 to +7°C) and frozen products (-18°C). To avoid the need for separate trailers for each temperature range, logistics companies often employ vehicles capable of maintaining both temperatures, with the diesel engine of the refrigeration unit directly driving the refrigeration compressor and (depending on the temperature to be maintained) having varying fuel consumption. Such consumption is significantly reduced by switching to a hybrid system with flexible solar panels.
It is essential to note that the photovoltaic panels available today differ significantly from those tested in 1998. The current panels are flexible, increasingly lightweight, efficient, and even more cost-effective. These characteristics are complemented by a high degree of customization, allowing for functional designs tailored to the requirements of transportation companies.
Among the industry's most intriguing options are panels with back-contact cells, which can convert over 24% of sunlight into electricity. This efficiency allows for high power generation even in limited spaces, setting new records for flexible modules.
We talked about this in the e-book dedicated to sustainable trucking. To learn more about the technologies and find out about the fields of application for flexible solar panels, download the free e-book below. It will be emailed directly to your inbox at no cost.