Solar Panels on Fleet Vehicles: Uses and Considerations

Fleet vehicles carry more electronics than ever: GPS units, ELDs, dashcams, multi-camera systems, asset trackers, lift gates, and sleeper or work loads. All of it draws from batteries. When a truck sits for days or a trailer is dropped at a customer site, those loads can drain batteries and leave you with dead trackers or a no-start.

Solar panels mounted on the roof, fairing, or trailer are one way to keep that power topped up. Early rigid panels were heavy and added drag. Newer thin, flexible panels can follow curved surfaces, which has made them more practical for fleets.

What fleets use solar for

Trade coverage of fleet solar use, including reporting from Heavy Duty Trucking, describes panels powering:

Battery maintenance: keeping starting and auxiliary batteries charged while vehicles are parked
Telematics and trackers: keeping trailer and asset trackers alive during long idle periods
Lift gates: extra charge for lift gate batteries on delivery trailers
Refrigeration unit batteries: on reefer trailers
Cab and hotel loads: battery-powered HVAC and sleeper accessories, to reduce idling during rest periods
Work vehicle loads: such as emergency lighting on some vocational vehicles

What fleets have reported

Results depend heavily on the vehicle, the duty cycle, and the climate, so treat these as examples, not promises. As reported by Heavy Duty Trucking:

One carrier described panels adding hours of battery-powered cab cooling, reducing idling, and extending battery life on hundreds of trucks.
Another fleet used six panels and four deep-cycle batteries to support a 10-hour quiet rest period, with an expected payback of about 3.5 years.
A third fleet put solar on trailers to keep tracking devices powered during long idle periods, which ended late-night calls to jump-start dead units.

Manufacturers also offer solar options for trailers, reefer units, and cabs. Some cab-mounted systems feed a converter that charges the battery directly so accessories can run without starting the engine.

Where solar falls short

Weather and season. Output drops on cloudy or rainy days and in short winter days. Systems that need power overnight usually pair panels with deep-cycle batteries for reserve.
Not every vehicle fits. Flatbeds have no roof to mount on. Covert trackers mounted under a trailer cannot use a roof panel without giving away their location.
Upfront cost. Panels, controllers, and batteries cost money up front. The return comes from fewer dead batteries, fewer service calls, and less idling, so it depends on how often those happen to you today.
It does not fix bad wiring. If a device drains a battery because it was wired to the wrong circuit, solar will hide the symptom, not cure the problem.

Questions to answer before you buy

What problem are you solving? Dead trailer trackers, lift gate batteries, no-starts after weekends, or idle reduction each point to a different system size.
What are the loads? List every device on the circuit and its draw, especially when the vehicle is off.
How long do vehicles sit? A few hours overnight is very different from two weeks at a drop yard.
Where will the panel mount? Roof, fairing, or trailer top, and whether the surface is flat or curved.
How will it connect? Panel to charge controller to battery, with proper fusing, sized for the system.
What does the vehicle or trailer maker allow? Check warranty terms and any guidance on roof penetrations or adhesives.

Install considerations

Mounting

Flexible panels are typically attached with adhesive or low-profile fasteners. The surface must be clean and suitable for the adhesive, and the panel should sit flat without trapping water. On cabs and fairings, keep panels and cable runs clear of moving parts and doors.

Cable routing

Every cable entry into a roof or trailer is a possible leak. Use proper sealed entry points, route cables away from sharp edges and heat, and secure them so they do not rub through over time.

Charge control and protection

Solar output should go through a charge controller matched to the panel and battery type, with fusing near the battery. Systems designed for fleet use often monitor battery voltage and temperature to keep batteries at a healthy state of charge.

Testing

After install, confirm the controller shows charging in daylight and that connected devices stay powered when the vehicle is off. Photograph the install and record the parts used, just as you would for a telematics device.

Start small and measure

Before outfitting the whole fleet, try solar on a handful of the vehicles or trailers that cause the most battery trouble today. Track a few simple numbers for a season: jump-starts and battery replacements, tracker or camera outages while parked, and idle hours if idle reduction is the goal. Compare them with similar vehicles that did not get panels. If the numbers move, you have a business case. If they do not, you have learned that cheaply.

Keep in mind that a Colorado winter and an Arizona summer will give very different results. If your fleet spans regions, include more than one in the trial.

Pair it with your telematics plan

Solar works best as part of a larger power plan for each vehicle type: what devices it carries, how they are powered, and how much they draw when parked. If you are already rolling out GPS, cameras, or asset trackers, it is the right time to look at power too.

TCI Installations installs flexible, roll-out solar panels and 12V power systems along with GPS, ELD, camera, and asset tracking hardware. We can work with the products you choose and fit the install to your vehicles.

Sources

Heavy Duty Trucking (Truckinginfo), How Fleets Are Using Solar Power
CCJ, Let the sunshine in: Use of solar can boost efficiency
Automotive World, DAF: Solar panels on trucks, less fuel, less degradation
Electrek, Adding solar panels to semi trucks helps slash diesel emissions (March 25, 2026)

Flexible and Roll-Out Solar Panels on Fleet Vehicles: What They Power and What to Consider