Carrier Transicold has expanded its line of thin-film flexible solar panels designed to help maintain peak performance of transport refrigeration unit (TRU) batteries in a more environmentally sustainable way.

The company now offers 18.5 watt (1.2 amp) and 9.24 watt (0.6 amp) solar panels, in addition to its original 28 watt (1.8 amp) model, accommodating a wider range of user needs and budgets. The panels are designed specifically to maintain TRU battery charge and can be easily installed on the roofs of trailers and truck bodies, chilled by Carrier or other systems.

Solar panels can offset the draw from accessory electrical devices, significantly reducing callout charges related to the battery, the company says. They can also help conserve fuel by minimizing the need to run the TRU engine to charge the battery.

The amorphous silicon, or ‘a-Si’, solar cell technology is said to provide high performance in real-world environments even where daylight may be indirect or low. They don’t need several days of sun-soaking to bring the panels up to full functionality, a useful differentiator. They also begin charging at a higher voltage at a lower angle of light than some other technologies, Carrier claims, allowing charging over a longer portion of the day, which is especially helpful in northern regions and in the winter.

When exposed to daylight, the solar panels continuously charge TRU batteries, ensuring ample power for system starts and helping to avoid issues and costs associated with a weak or dead battery. Refrigeration-system batteries are often tapped to power additional trailer electronics such as telematics devices, fuel-level sensors, interior lighting, and other accessories. If the TRU has not been operated for some time and these accessories continue to draw power while the unit is off, its battery might not have enough charge to start the engine.

These solar panels are said to be light and highly flexible, and they measure less than one-eighth of an inch thick. Designed to withstand the harsh transportation environment, they are waterproof and puncture-resistant and have a five-year limited warranty on power output.