Solar technology for trucks has progressed to a point where more fleets are investing in it. Way back in 2017, two of the trucks in the very first Run on Less were outfitted with solar panels.

The main reason fleets are installing solar panels on their tractors is to support e-APUs and hotel loads because solar panels can help extend the runtime of those devices without draining the truck’s main batteries. Solar panels also help reduce the load on the alternator. They can also augment the energy coming from the truck’s batteries, keeping them at a higher state of charge and extending battery life.

I have experienced this first-hand as the last three recreational vehicles I have owned have had a significant number of solar panels on top of them. In fact, I had eight panels on the coach that we full-timed in from 2016-2020. They worked well and allowed us to meet all electricity needs when “boondocking," parked with no electric hookups.

Solar panels designed specifically for the trucking industry are flexible, thin, lightweight, and can be affixed to the curves of the tractor’s fairing as well as to the top of trailers.

In addition to having solar panels on the tractor, some fleets are adding them to the trailer. Trailers have traditionally been powered by the seven-way connector between the tractor and the trailer, which powers brakes, running lights, etc. Recently, several other electrical loads have been added to trailers, and many of those electrical demands can be supported by solar panels. Trailer solar panels can help support liftgates, telematics, and refrigeration units.

There are some best practices for determining if adding solar panels makes sense for your fleet. Fleet managers need to consider factors such as total energy produced. These include fuel saved by the panels, panel lifespan, battery life extension, and the fleet’s total energy profile. Fleets also need to evaluate the cost of installing the system, panel ratings vs. their physical size, the fleet's battery replacement rate, the typical number of roadside calls for jump starts or battery replacement, and the areas of the country in which the fleet operates.

When considering adding solar panels to the tractor, include cost savings from reduced idling, less load on the alternator during normal tractor-trailer operation, increased battery life, and fewer emergency roadside assistance calls.

When considering solar panels for trailers, analyze the electrical requirements of liftgates, refrigeration units, telematics devices, lighting, pallet jack charging, duty cycle, cost savings from increased battery life, and the number of emergency roadside assistance calls.

One important note when it comes to solar panels: they must be sized appropriately for their intended application. For example, the size of a solar panel to support an eAPU on a tractor might be limited by the area available on the tractor fairing, whereas a solar panel to support a refrigeration unit only needs to be large enough to provide a small trickle charge to the reefer unit’s starting battery.

If you have not considered solar panels in the past, now might be a good time to evaluate whether they make sense for your application.