The Nissan Leaf is great, but the sad reality is that we’re still many years away from electric vehicles replacing a significant percentage of our cars and trucks. Battery costs are high and ranges are comparatively short. Those problems are even more salient for semi-trailers, which need to carry heavy loads long distances. Our current batteries just aren’t going to cut it.
But until they can, we can still make improvements to the semis we have. At this year’s Trailer 2011 exhibition (yes, it’s a trade expo for trailers), Mercedes-Benz is presenting a design study for a new aerodynamic trailer that reduces wind resistance by as much as 18% as compared to their existing Actros trailer.
The "Aero Trailer" sports a number of small design improvements that allow it to cut through the air more easily. The two most significant features are those side trim panels, which reduce resistance by 8%, and the tapered rear end, which contributes another 7% reduction.
The "Aero Trailer" is still just a design concept, but Mercedes says its features would result in a 5% fuel savings. That might not sound like a lot, but a truck that travels 93,000 miles in a year would save 528 gallons of diesel fuel and five tons of carbon dioxide.
And freight trucks rack up a lot of miles in United States. According to the Department of Transportation, in 1997 approximately 21 million trucks traveled more than 412 billion miles in the United States. The DOT estimates the volume of freight will rise by 70% by 2020.
Wind resistance improvements are not going to stave off climate change by themselves, but they’re certainly a step in the right direction, given that we’re stuck moving a certain amount of stuff with these trailers for the foreseeable future.
If you’re curious, by the way, electric (and hydrogen) freight trucks do exist. The Port of Los Angeles has been experimenting with them since 2008. They just can’t go very far.