Despite a long career in the trucking industry, Mike Roeth admits, he was largely “ignorant” about yard tractors deployed by fleets to spot and move trailers in large freight depots.

“I knew they existed. I’d seem them around. But I hadn’t given them a lot of thought,” the executive director of the North American Council for Freight Efficiency told reporters in a March 6 briefing at the American Trucking Associations’ Technology & Maintenance Council meeting in Orlando, Florida.

That changed after NACFE wrapped up its Run on Less Electric fleet efficiency demonstration late last year. Run on Less Electric tracked 13 North American fleets using battery-electric vehicles to do their daily work. This included everything from small box vans all the way up to Class 8 electric trucks. And the study included electric yard tractor operations, as well.

After Run on Less Electric concluded, Roeth and other NAFCE analysts concluded that electric yard tractors may be a great first step for fleets interested in learning more about electrification in commercial vehicle applications.

Roeth noted that the timing is important as well. Yard tractors will soon be subjected to emissions regulations that require the use of selective catalytic reduction exhaust systems to remove NOX emissions from diesel exhaust similar to those for on-road trucks.

“We found that terminal tractors is a tough duty cycle for exhaust aftertreatment,” Roeth said. “That may very well affect the life of these trucks to the point that fleets will not be able to get as many years of service out of them as they do on prior generations of diesel-powered yard tractors. Electric powertrains may be the perfect solution to that problem.”

Additionally, because electric yard tractors typically spend their entire lives working at one domicile, they’re easier for fleets to study, perform maintenance on and generally get a feel for how the technology performs. And they won’t be stranded in the middle of nowhere without a charge.

Roeth listed four key points on why NACFE thinks yard tractors make sense as a stepping-stone for fleets interested in BEVs for fleet applications:

1. Simplified vehicle designs and avoiding emissions regulations is driving development and acceptance of electric terminal tractors.

2. Battery electric terminal tractors can be used inside warehouses and not just outside in yards.

3. Electric terminal tractors provide more uptime and simplify operations.

4. Electric terminal tractors are a good fit for firms already using electric material handling equipment.

One big takeaway from Run on Less Electric for using electric terminal tractors successfully is the use of “opportunity charging,” Roeth added.

“That’s a term we really like a lot,” he said. “It simply means taking every available opportunity you can to charge an electric truck during the day or during a shift. If a truck pulls into a grocery store, that can mean a half an hour to an hour of charging time while the groceries are being unloaded.

“For an electric terminal tractor, that can mean operating for three hours and then charging for 20 minutes. We found many fleets running them have set up charging stations near their offices or driver break rooms. That enables opportunity charging during restroom, meal or snack breaks, or while the driver is doing paperwork. That can go a long way and make a big difference toward extending the daily range capabilities for these trucks.”