Recent news of semi truck innovation has largely centered in hybrid models that doubled fuel economy or used natural gas for cleaner operation. Those are amazing stories of the industry pushing forward, but there’s another important component in national transport: the semi trailer itself.

Power and engine technology are indeed the muscle behind the motion, but the manufacturers behind refrigerated trailers have unveiled something recently as well — namely using solar power to maintain the refrigerator’s power supply.

Anyone who’s used air conditioning in their homes or cars knows it takes a lot of power to make that happen. Imagine refrigerating an interior space the size of a semi trailer, and at much lower temperatures. This can create additional consumption on the semi truck’s engine having to power the refrigeration unit, which has often made refrigerated hauls more expensive.

In addition to fuel savings, this also prevents up to an estimated 50.5 tons of carbon dioxide emissions per year.

For daytime hauls with full sun, panels installed along the top of the trailer and truck components can store up to 100 hours of energy. That can then be used when the battery drops to 30% during operation. The long term goal for these companies is to arrive at a zero emissions operation, where transporting refrigerated goods generates no additional emissions beyond what the semi truck itself creates.

That thinking pairs well with the recent innovations in engine technology employed by Freightliner trucks. With specialized systems to keep emissions as low as possible, the trucks themselves are creating a smaller carbon footprint than ever before. Attach a solar-powered refrigerated trailer to one of these bad boys and you’ve got a package with the lowest operating cost the industry has seen.