Mesilla Valley Transportation recently purchased close to 1,000 eNow solar auxiliary energy systems for its fleet of Navistar trucks. It’ll be one of the technologies showcased on MVT’s entry in the "Run on Less" fuel economy program next month put on by the North American Council for Freight Efficiency.

"We're always looking for innovative, more effective and efficient ways to operate," says Royal Jones, CEO and president of MVT. "Our daily idle time is less than 6% on the whole company fleet and we utilize electric APUs 100%."

The problem is, the electric APUs typically don't last the full rest cycle for drivers, especially in the American Southwest where much of MVT's fleet operates. The solar panels help the electric APUs keep drivers comfortable the entire rest period, Jones explains. In addition, "Over time we had noticed shortened battery life and shortened alternator life due to the demand on batteries and the fact that we run eight batteries."

In testing the solar system from eNow, MVT noted increased daily run time for auxiliary equipment, such as in-cab HVAC; increased battery life from six months to two years; saving approximately 3 gallons of fuel per day from reduced engine idling; and decreased maintenance cost due to reduction in engine idling.

That testing, combined with Navistar's testing of the eNow system on its CatalIST SuperTruck at Navistar Proving Grounds, led to the purchase of the eNow energy systems for the MVT fleet. 

This wasn't MVT's first foray into using solar power. MVT had tried making its own system about five years ago, before flexible solar panels were available to the industry, but abandoned the effort when it discovered the loss in aerodynamics created too much of a fuel economy penalty. But it didn’t take the panels off the test trucks, and later it found those trucks didn’t need the yearly battery replacement its other trucks do. Now it is running several hundred trucks outfitted with the eNow panels.

With the eNow eCharge system, solar photovoltaic (PV) panels are mounted on the roof of the tractor, trailer, or both. The PV panels capture sunlight and convert it to direct current (DC) electricity. The DC electricity goes to eNow’s proprietary solar charge controller, which maximizes the power output of the PV panels and then sends the power the vehicle’s battery system. eNow’s eCharge provides full-system charging, supplying more than enough power to charge the batteries and run auxiliary equipment.