Right Size, Right Place: EV Charging Infrastructure Decisions that Drive Success

Across the country, utilities are faced with a challenge: customers require more public electric vehicle (EV) charging infrastructure to feel confident buying EVs, yet the complexities of charger installation at commercial properties can result in lengthy timelines and skyrocketing costs. To benefit from this once-in-a-lifetime increase in electric load—which has the potential to boost utilities’ bottom lines and put downward pressure on electric rates for all customers—utilities must tackle this issue on a variety of fronts.

In addition to innovative solutions such as streamlining energization timelines (under consideration in California), making proactive infrastructure investments at sites forecasted to be EV charging hot-spots (contemplated in Massachusetts), and pre-ordering inventory of critical electric grid components such as distribution-level transformers (implemented at Orange & Rockland Utilities in New York), utilities can take simpler steps as well. One straightforward solution is to work directly with site hosts (commercial customers installing EV charging on their property), who are often new to the EV space, and guide them toward installing the right charging infrastructure for their site type. Early involvement from the utility can ensure that these customers’ service requests are attuned to existing grid constraints—streamlining timelines and reducing costs—and it can also strengthen the site host and EV driver experience.

Customers Need Guidance

Customers who are unfamiliar with EV charging often think that bigger, faster EV charging is always better. Why install measly 7 kW Level 2 chargers when you could instead host a 350 kW DC Fast Charger (DCFC)? Mentally, these customers may be comparing EV charging to the gas station experience—rationalizing that drivers want to get in and get out as quickly as possible. But as many EV drivers know, it’s important to match the EV charging speed at a public charging site with the characteristics that brought the driver there in the first place. When it comes to EV charging, too slow is a drag—but too fast can be equally frustrating.

As a rule of thumb, the best EV charging speed for a site is as slow as possible in a way that still meets the driver’s use case. Utilities should actively work with commercial property owners to support their decision between installing Level 2 (3-19 kW), lower-powered DCFC (30-100 kW), or higher-powered DCFC (125+ kW) EV charging.

Low and Slow, Go with the Flow

Level 2 charging is best suited for sites where vehicles are parked for 2-8 hours at a time. This could be multifamily properties, workplaces, large retail sites (such as malls), curbside charging in residential neighborhoods, airports, movie theaters, parks, or schools. Were these sites to install DCFC instead, they might find that drivers stay for shorter periods—or are inconvenienced by having to move their fully-charged car before they are ready to leave. For fleets, if vehicles are parked overnight, Level 2 charging can be perfectly adequate—even for medium- or heavy-duty vehicles with limited duty cycles, such as school buses.

For public charging, site hosts should know a few things about Level 2 charging. First, Level 2 is more frequently used opportunistically by drivers than as a destination. Level 2 charging may be the thing that helps a driver select your site over a competitor’s or keeps a driver at your site for longer, but it’s unlikely to be the primary reason for a driver to visit your site in the first place. For that reason, site hosts might consider offering Level 2 for free or at a low cost to drivers, and endeavor to recover installation and operating costs through increased sales or employee/tenant satisfaction or retention. These sites should also consider the importance of charger placement—drivers are unlikely to be willing to park in the back corner of the parking lot just to plug in to a Level 2 charger. Luckily for these site hosts, Level 2 chargers are considerably less expensive than DCFC, and they typically require fewer grid or site upgrades to install (which means less cost and faster energization timelines). Level 2 chargers put less strain on the grid, limiting the demand charges that can make up a substantial portion of the energy bill, and are also easier to maintain (especially if driver payment isn’t required).

When More Zip is Required

By contrast, some sites—where vehicles typically park for 30 minutes to an hour—are better candidates for DCFC. These include gas stations and convenience stores, truck stops, grocery stores, retail plazas, big box stores, and coffee shops or fast casual eateries. In the fleet realm, DCFC is best for high-turnover vehicles such as rental cars, or larger vehicles such as transit buses.

EV drivers view DCFC—especially the higher-powered units of 125 kW or more—as a destination. Sites with this type of DCFC will see plenty of foot traffic from road trippers, as well as from drivers who live nearby but lack access to charging at home. In these cases, offering DCFC can be a compelling competitive advantage for the site, so long as it provides adequate amenities in the form of shopping, food and beverage options, and restrooms. These sites will benefit from the high turnover of DCFC, especially if each driver buys something. While installing DCFC is undoubtedly more costly on the front end for these customers (both in time and in treasure), sites that opt for Level 2 to save money may find their chargers underutilized due to the mismatch in charging time and vehicle dwell time. Underutilized chargers are a shame, especially for site hosts who were hoping to enhance their site with a new amenity.

For sites that fall in between the two ends of this spectrum, or sites that are good candidates for DCFC but have existing grid constraints that would be costly to overcome, lower-powered DCFC (50-100 kW) is a third option that might work. Many older EVs cannot take advantage of higher-powered fast charging anyway—for example, a 2018 Chevy Bolt maxes out at 60 kW, whether it’s plugged into a 75 kW charger or a 350 kW one. And for fleets, a medium charging level (whether 19 kW Level 2, or 50 kW DCFC) might be the perfect fit for their vehicles’ duty cycles and dwell times.

The Utility Role

Utilities can offer technical assistance to support their commercial customers in navigating the decision-making process for installing EV charging. Utilities should develop collateral and customer consultation sessions to help customers and site developers explore questions about their site type and their goal in installing EV charging. Utilities must also provide information about existing grid infrastructure (e.g., hosting capacity maps) and swift assessments of the cost and timeline to perform any necessary upgrades to ready a site for EV charging. By offering formal programmatic support—or even by simply staffing the new service request process with a couple of EV charging experts—utilities can help customers leverage capacity within the existing grid. This will save the utility and its customers time and money, driving satisfaction for site hosts and EV drivers, and ultimately, accelerating EV adoption.