When it comes to charging, electric vehicles (EVs) come in a variety of options — not all of which play nice together. Between charger plugs that vary from manufacturer to manufacturer and the requirements of Level 3 fast-charging stations, knowing what the most effective investment in infrastructure is for your development needs can be difficult.

Understanding the basic levels of EV charging available, the relative market penetrations of different plug types and the changing needs of EV owners can go a long way in helping determine what charging infrastructure will work for your needs.

The 3 Levels of Charging

In EV charging, there are three levels describing both speed of charge and voltage type.

Level 1 chargers are designed for low power alternating current (AC) applications. Charging is slow, providing about 5 range miles per hour, and the charger can usually be plugged into an everyday, run-of-the-mill wall outlet of a residence.

Level 2 chargers deliver higher voltage AC for faster charging — up to 20 range miles per hour — and are normally plugged into a 220-volt outlet or hardwired into a residence or building.

Level 3 charging is the highest level, offering fast charging through direct current (DC). At this charging level, an offboard system contained in a large installation converts AC to DC. This allows the charger to deliver more power than in Level 1 or Level 2, in which the AC-DC conversion is done onboard the vehicle. Level 3 charging is used for both consumer passenger vehicle needs and in commercial applications, such as shipping and transit buses, where opportunity and fast charging are required.

In Level 3 charging — at a very basic level — DC current is pushed directly into the EV’s battery. While this is simple enough, issues begin to arise when it comes to the communications between the charger and the EV. The EV is designed to communicate with the charger through the communication connection on the plug, essentially asking the charger to provide the desired amount of power at the level of voltage needed to effectively and safely charge the battery. Going beyond these voltage boundaries can damage the battery.

CHAdeMO vs. CCS

Generally, there are two main Level 3 plug types for non-Tesla EVs. CHAdeMO plugs were developed through a partnership between Tokyo Electric Power Co. and automotive manufacturers in Japan. They are typically fitted to Japanese EVs. The Combined Charging System (CCS) charger, which was developed by the Society of Automotive Engineers, a primarily North American organization, is commonly fitted to EVs manufactured in North America and Europe.

Despite both serving the same purpose, differing pin configurations on these plugs make them incompatible. Communication and voltage regulation protocols for each are also different, so creating an adapter is both technically challenging and cost-inefficient.

Electrify America — a subsidiary of the Volkswagen Group — owns and manages an EV charging network, having installed 2,000 DC fast chargers at 484 sites in 2019 alone. At each site there is typically only one or two CHAdeMO plugs for every four to 10 CCS plugs. This installation ratio is likely due to the heavy market penetration of CCS plug vehicles in North America. However, since this group has a vested interest in using and distributing a plug type compatible with certain vehicles, that may have played into their decision making.

As a result of these issues, EV Level 3 chargers using the CHAdeMO charger type are less common in the U.S., further complicating the ability of developers to decide on effective infrastructure for their areas.

The Need for Charging Infrastructure

It’s important to think about the relative market penetration of plug types when considering the possibility of adding charging infrastructure. Developers must ask themselves if it makes sense to include a 50/50 split of CCS and CHAdeMO chargers, or if there is a ratio that can be followed that would meet the needs of area consumers.

Additionally, property owners must understand the relative needs of the surrounding areas by considering how much at-home charging takes place as opposed to charging outside of the home. This leads to the larger question of how much charging infrastructure is actually required in a given area, as most residential EV drivers are going to charge up at home overnight.

However, it is possible to argue that charging infrastructure helps to normalize EVs as a whole, making them seem more accessible and giving the public a more positive association with charging and EV infrastructure by soothing range anxiety. In fact, according to a 2016 report titled “The Market for Electric Vehicles: Indirect Network Effects and Policy Design” by Shanjun Li, Lang Tong, Jianwei Xing and Yiy Zhou of Cornell University, studies have shown that the addition of EV infrastructure to an area boosts the EV market.

Moving Ahead

It’s clear that there are many factors to consider when determining what charging infrastructure will be the most effective choice. EV station installers and owners must understand the needs of the community in order to find the level of charging, the number of stations and the types of plugs that will be most beneficial to consumers. Taking these things into account will lead to a more cost-efficient, executable plan for buildout.

 

Moving to a 100% electric fleet is a daunting undertaking, requiring a large investment and new infrastructure. Building a plan can help map out the road forward.

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Andrew Milian is an electrical engineer at Burns & McDonnell. He focuses on finding innovative electric vehicle (EV) infrastructure solutions for large Level 2 charging programs and Level 3 installations.