What do battery-electric truck charging stations need to function?

Battery-electric Class 8 vehicles are entering the trucking space, and government entities are working to promote the electrification of freight. As decarbonization efforts and pushes increase, electric trucking operations are leading the charge.

Fleet leaders considering electrification will want to know: What does a charging station need to operate, and how much power would it draw?

Charging stations for heavy-duty EVs have several demands. They need to have appropriate amenities, allow enough space for heavy-duty vehicles, be in ideal locations, and provide significant power.

General station needs

Just like fueling stations, charging stations for heavy-duty vehicles have needs beyond those for passenger vehicles, from amenities to upkeep and space.

Ideal charging stations should include amenities for drivers, including an area with food, beverage options, bathrooms, Wi-Fi, a lounge to sit in, and security measures, Sibley said.

A charging station also needs to have the space to accommodate heavy-duty EVs.

“The stall size is also different," Sibley told FleetOwner. "There are larger stalls to support larger vehicles. Often, we are designed for pull-through stalls so truck drivers can have the easiest access to the charger, not have to back in/back out of the stall with a tractor-trailer. That also means wider aisles.”

Ideal electric charging stations for commercial vehicles also have a reservation system to book charger time, a waiting area for drivers while their vehicles charge, and reliability measures to maintain uptime.

“What we’ve seen is, largely speaking, one of the biggest challenges that’s often experienced in that initial phase is the reliability of the chargers themselves, which has been relatively lower as far as an uptime metric goes,” Ryan Kennedy, co-founder of Atom Power, told FleetOwner.

Sibley mentioned that reliability measures can include dedicated software, tools, charger management systems, and technicians.

At a smaller scale, most charging stations are built for fleets at their facilities.

“Most development is happening at customers’ own facilities behind the fence, but they are beginning to branch out into off-site charging as well,” Sibley said. “The reason for that is that a lot of customers’ owned facilities simply don’t have the space or the power to accommodate charging at their own facilities.”

Station location

Countless variables influence exactly where charging stations can be built.

At the national level, chargers are appearing most where incentives and mandates help to drive EV adoption, Emilia Sibley, head of solutions for charger infrastructure company Terawatt, said.

“California is where we’re seeing most of the activity today, but it is starting to branch out from California too,” Sibley told FleetOwner. “Places in Texas, New York, the Pacific Northwest, and along the Eastern seaboard.”

On-site charging with low power

Initial charger deployments at lower power can work well on-site at a fleet’s established facility.

“The vans and box trucks are going to have battery packs that are in the 100 to 250 kWh battery packs. If you’ve got a very solid 6 hours to charge them overnight, or maybe up to 10 or 12, then you could charge that whole battery pack up with a 50 kW charger,” Mike Roeth, executive director of the North American Council for Freight Efficiency, told FleetOwner. “And that charger is an order of magnitude—10 times cheaper—than a 350 kW charger, or even maybe a 150 kW charger. ... You can save a lot of money on chargers going with slower, passenger car kinds of chargers.”

This low-and-slow charging approach works best for lighter commercial vehicles running regular, brief trips. Electrification at a larger scale, running more vehicles or larger battery packs, brings power needs that can exceed a facility’s capacity.

When charging station power needs exceed capacity, it requires an upgrade to the power infrastructure. This can often include a facility-side upgrade to the building’s electric equipment or a utility-side upgrade to nearby transformers, Ryan co-founder of Atom Power, told FleetOwner. Both on-site power upgrades can be costly and time-intensive.

However, developing a new, private charging station outside the facility can still prove very costly. At this point, organizations may prefer sharing a station with other fleets. Terawatt works to develop charging stations that can accommodate multiple customers at once.

“Our charging solutions are typically what you call semi-public, in which we serve a set of fleet customers with paired but private charging stations,” Sibley told FleetOwner.

Sibley said that Terawatt’s charging stations generally develop in areas where it makes the most sense to locate shared facilities. “We locate them near zones of concentrated freight activity,” Sibley told FleetOwner. “Near ports, intermodals, warehouses, and on freight corridors.”

The company’s customers are also most interested in charging stations located very close to their facilities.

Chargers’ energy demand

Charging stations for heavy-duty EVs have significant energy needs.

“Trucks have larger batteries than passenger vehicles, and so it requires a faster charger to fill up that battery in the appropriate amount of time,” Sibley said.

Powering a 3.5 MW charging station entirely through solar panels would require about 25 acres of panels on a sunny day.

Today, most trucks accept power at a rate that’s lower than the fastest available chargers, Sibley told FleetOwner. “Public chargers available on the market are really maxing out at 350 kilowatts, so that’s what we install in order to offer the fastest charging on the market under CCS [Combined Charging System]. The vehicles themselves right now, the heavy-duty electric trucks, can accept around 250-270 kW, putting Tesla Semi aside.”

CCS is a standard for charging most electric vehicles. Tesla vehicles use its own separate standard: the North American Charging Standard.

Sibley said that Terawatt prefers to install 350 kW chargers since they are faster than what trucks can accept today and help to future-proof stations for the next generation of trucks.

“We like to sort of phase in power at our sites: start with a few megawatts, then, as customer demand increases, we’re able to bring in more power and match that demand curve over time,” Sibley said.

A typical first phase for Terawatt is to install 10 stalls at 350 kW each, totaling 3.5 MW of power needed for the site.

For scale, providing 3.5 MW entirely through solar panels would require about 25 acres of panels on a sunny day, according to the average size of a megawatt solar farm in Wisconsin. Station developers will want to look for ways to reduce power draw through onsite solutions.

“Solar is becoming a piece to this too,” Roeth said. “Oftentimes they’re going to put canopies over the top of the charging areas or even some of the parking areas to protect the trucks from the sun but also to just harvest that sun for charging.”

The first-phase site can also be prepared to support more chargers in the future. Grid utilities are also building infrastructure to provide more power in places where companies like Terawatt are requesting it.

However, the characteristics of a typical heavy-duty EV charging station are still changing.

“I think the industry is still figuring out what that typical ideal station looks like,” Sibley told FleetOwner. “If you look at diesel fueling stations, for example, they often are not more than 10 stalls at truck stops. You’re not seeing as many as, say, 60 stall fueling stations—but that’s also because it takes a lot less time to fuel a diesel truck today than an EV.”