Charging and maintaining electric trucks will be no small task
Posted: March 22, 2019 by John G. Smith
ATLANTA, Ga. – NFI International’s drayage fleet seems to be a great fit for battery-electric vehicles. Its Class 8 trucks run the same predictable routes time and again, traveling just 174 km to the ports of Los Angeles and Long Beach, California.
Adding one or two such trucks would be relatively easy, says Bill Bliem, senior vice-president of fleet services. A required 90 kW charger can be installed within weeks, and California offers some of North America’s richest financial incentives to offset price premiums for the vehicles themselves.
But NFI plans to introduce 15 battery-electric trucks by the end of the year — and that will be another matter entirely. Decisions to electrify more than a handful of the units demand some big thinking to address the challenges of big chargers, big cables, and big investments for the related infrastructure.
While an average household consumes about 909 kWh of electricity per month, a Class 8 electric truck will use about 2.3 kWh per mile, Bliem told fleet managers at the recent annual meeting of the Technology and Maintenance Council (TMC). “That means we’re going to get one day of work out of a month’s worth of household energy consumption.”
It also means the related chargers will have little in common with their automotive counterparts. A Nissan Leaf can be charged overnight using a typical 120-volt outlet. Household garages featuring 240 volt/80-amp outlets do the work in half the time.
Automotive-grade CCS DC fast-chargers can bring a 100 kWh battery up to an 80% charge in less than 20 minutes, delivering around 1,000 volts and 500 amps and drawing 250-500 kW of power. Proposed commercial vehicle chargers will deliver 1,500 volts and 3,000 amps to charge 500 kWh batteries in 20-30 minutes and require 4.5 megawatts of power, said Brent O’Daniel, a project manager with the charging experts at Black and Veatch.
“This,” he said, “is going to present some significant challenges.”
Setting the electric vehicle charging standard
The charging cords alone will be thick and unwieldy and can only be so long before they lose their charging capabilities, said Mike Hasinec, vice-president of maintenance at Penske Truck Leasing. Tethered connections will support some of the weight, but there will still be some heavy lifting to do.
To compound matters, the trucking industry has yet to decide on a standard for chargers or even decide where receptacles should be mounted on the trucks themselves.
The lack of a common charging standard has already led to challenges with electrified light-duty vehicles, which might draw their power from SAE1772, CCS Combo, CHAdeMO, or Tesla DC chargers. “It can be quite the hassle to find the right plug adapter and kilowatt rating,” O’Daniel said.
A group known as the CharIN task force – representing more than 70 manufacturers, component suppliers, utility companies, and other related businesses – has worked for more than a year on standards to govern how heavy vehicle charging systems should be designed, built, operated and maintained. It’s expected to unveil a winning design this June.
Even when those standards are set, charging infrastructure will require significant investments, assuming that local utility providers are able to deliver the required power to a preferred site.
Bliem said NFI expects to pay about $100,000 for a DC charger. That doesn’t begin to account for the fees linked to engineering, trenching, conduit, panels, and the transformers to align with local utility requirements.
Managing electricity costs can be challenging, too. Unlike diesel, the price of this energy source can vary by the time of day as well as geographic area. Special software, which comes with a monthly fee of its own, might be needed to manage the energy flows and avoid demand-related charges. Then there is the need to feed details about a truck’s state of charge and consumed electricity into back-office systems.
“We also have to look at our backup power solutions. What are we going to do if we don’t have enough electricity?” Bliem asked. His fleet expects it would need a 300-hp generator to meet such power demands. Other options being explored include solar panels and storage walls that could repurpose used electric vehicle batteries.
The fleet’s landlord still needs to be sold on the idea of the solar option. Said Bliem: “We don’t want to make a million-dollar investment in a site that we lease.”
Finding a home for the chargers is no small matter, either, and not just because the areas prone to flooding will need to be excluded.
“There’s a lot of real estate involved,” Bliem said, referring to the way most fleets park tractors in front of trailers. Delivering the charging infrastructure to all those locations will likely be impractical, meaning that battery-drained trucks will have to bobtail to their charging stations.
“The vehicle is going to be there a while. It’s not like your fuel island, where 15-20 minutes later you have throughput,” Hasinec added. And with charging ports mounted at different spots, fleets will need to consider whether trucks are going to back up or pull in to position.
Penske facilities usually have full-service fuel islands in place, but he doesn’t expect pull-through charging lanes anytime in the near future. “When it comes to public stations, I think there’s a lot of work to do when it comes to megawatt chargers.”
O’Daniel listed other charging station considerations including cord lengths, traffic patterns, equipment clearance requirements, and a landlord’s plans for future expansion. “It’s best to ensure there are no easement restrictions from your landlord or local utilities,” he stressed, referring to right-of-way restrictions.
In the midst of it all, Bliem continues to monitor efforts to develop wireless charging systems, which are already proven to work with some buses. Who knows where that work will lead?
Maintaining electric trucks
Bliem is also wary about promises of drastically reduced maintenance costs, even though electric trucks will feature fewer components than their diesel-powered counterparts. “Nobody knows,” he said. “That’s an assumption yet to be proven out.”
Penske’s Hasinec leaves no question that maintaining such equipment will require different tools and thinking inside a shop.
Any hand tools need to be insulated, he said as an example. Multimeters used on electric vehicles also need to be rated up to 1,000 volts – well beyond the range of those used in a diesel shop. Then there are the special tools need to deenergize the vehicle before work begins, and a 240-volt charger to apply power when needed.
“When it comes to electric vehicles, safety is a must,” Hasinec said, referring to the importance of providing each technician with personal protective equipment (PPE). Even that will require some special oversight. Class 0 or higher gloves need to be recertified semi-annually, and arc shields are only rated for exposure to a single flash. Techs with internal medical equipment such as pacemakers will need to be assigned to other tasks.
Setting aside a designated area for the work will help to keep everyone safe, and not simply because of the potential electrical exposure. “These vehicles are very, very quiet, so they may actually be in the read-to-run situation and you may not even know it,” Hasinec said.
Everyone working in and around the shop will need to be trained about basic do’s and don’ts. Technicians who work on the vehicles themselves will need electrical know-how and an unwavering focus on the lockout and tagout procedures to be followed before work begins. The high-voltage training will wait, though. In the early days, OEMs will be asked to service the electric motors and batteries, he said.
The underlying planning will involve a fleet’s risk management team, working with a local fire department to develop protocols for things like battery thermal events, and asking tow providers to demonstrate how they would move such a truck without damaging the all-important electric motors.
As for knowing how to conduct the repairs? Each new truck will come with a new set of fault codes, and some of the service literature hasn’t even been developed, Hasinec said.