This is part two in a series dedicated to helping electric utilities prepare for a future with wide-spread electric vehicle (EV) usage.
As climate change continues to worsen and renewable energy becomes ubiquitous, electric vehicles (EVs) will become more prevalent. This means that utilities will be responsible for investing in new infrastructure to support expanded EV charging, both in residential and commercial areas.
In simple terms, the two key types of electric vehicle (EV) charging are fast charging and slow charging. Fast charging is a commercial form of charging, comparable to refueling at a gas station. Slow charging typically takes place overnight at a residence.
Each type of charging will require electric utilities to invest in new infrastructure, both in residences, as is the case with load sequencing panels, and around town, with new construction of transmission lines, distribution lines, and substations. While urban and suburban areas will require some infrastructure build-out, vacation areas will require substantial new infrastructure.
Let’s take a closer look at the pros and cons of each of these two charging types, and the infrastructure investment that will be necessary to support increased EV charging.
Pros and Cons of Slow Charging Electric Vehicles
There are many positives to slow charging technology for electric vehicles. Slow charging works well when EV owners travel less than 100 miles per day and return to single family homes every evening. Four kilowatt charging equipment is relatively inexpensive to install. Electric utilities will experience a minimal impact on their transmission and distribution systems with this form of charging.
Difficulties arise when residents have more than one EV. Every EV slow charger has a load of 20 amps, about 10% of the capacity of a 200-amp circuit breaker panel. This is a relatively small percentage of the total capacity, so a single EV has little impact. However, it adds up quickly.
Two EV slow chargers will be a load of 40 amps, or 20% of the capacity of a 200-amp circuit breaker panel. When an air conditioner, water heater, clothes dryer and electric stove are also in use, charging two EVs at the same time would overload a 200-amp service panel and cause a power outage in a residence. This is why slow chargers are not very practical for multi-family dwellings, such as apartments or condos.
Load Sequencing Panels Improve Slow Charging Performance
To improve the utilization of slow chargers, or accommodate for multiple EVs charging at one residence, residential owners could install load sequencing panels (LSPs). LSPs allow consumers to track and alter their energy consumption based on a variety of factors, such as the cost of energy. In the case of EVs, LSPs can be used to program specific circuit activation time to avoid overloading the service panel. This technology prioritizes energy consumption in certain circuits, so that multiple slow chargers are not activated at the same time as other household appliances.
Residents control LSPs via app and can use them to shut off power to specific circuits with interruptible loads when EV charging (or other energy usage) is essential. By shutting off circuit breakers on interruptible loads, such as water heaters or outdoor lights, more energy can be available for EV charging without the risk of causing a power outage. LSPs can also be used to schedule a charging time for each EV, so long as the chargers are on separate circuits.
Note that some circuit breakers, such as those that power refrigerators, must always remain on. LSPs would be programmed by the user to never shut off circuits that power these essential loads, even when energy is required for EV charging. Learn more about this innovative technology in our other articles, including:
Fast Charging: A Necessary Expense
Fast charging via commercial charging stations will be needed for a variety of circumstances. Some EV owners may travel more than 100 miles per day, and may not return to their homes every evening, such as while traveling for work or on vacation. EV owners may live in multi-family dwellings that cannot support enough slow chargers for every EV.
Fast charging stations will be needed at rest areas along major highways and at locations that currently house gas stations, as well as in vacation and resort areas. New infrastructure will need to be constructed to support the build-out of new EV fast charging stations.
For some electric utilities, this will mean only a modest investment in new transmission and distribution systems. Other electric utilities will need to invest hundreds of millions of dollars to build new distribution lines, substations, and transmission lines.
Electric Vehicle Charging in Vacation Areas
Vacation areas attract millions of tourists during their busiest seasons. Some will visit for the day; others may spend a week or more away from their homes. Vacation areas will need to invest in fast charging options to accommodate the peak number of tourists in a season plus their year-long residents.
Consider, for example, Atlantic City, New Jersey. A single casino will need the facilities to charge 2,000 EVs in four hours during the summertime. The casino may only have 1,000 hotel rooms, but not everyone who wants to charge their EV will be staying at the hotel. Some chargers will be used by vacationers on day trips, some will be used by people attending concerts and shows at the casino, and yet others may be used by hotel and casino staff.
When considering that fifty or more hotels and casinos will want to provide fast charging for up to 2,000 EVs in four hours, it’s likely that significant investments in new electric energy infrastructure will be needed. The electric utility supplying Atlantic City will likely need to build twelve new distribution lines, three new substations, and three new transmission lines to accommodate charging the EVs of vacationers every summer.
EV Charging in Regularly Populated Areas
Regularly populated areas, such cities or suburbs, will also need new infrastructure to support increased EV charging. Consider, for example, Hillsboro, Oregon, a city with 100,000 residents and about 20 gas stations. With a diverse population, it’s likely that in the near future, Hillsboro will need facilities to charge 1,000 EVs per hour. The electric utility that supplies Hillsboro will likely only need to build two new distribution lines to support EV charging.
The investment for this utility will be significantly less than for the utility that provides power to Atlantic City. However, investment in all areas is vital to support a future with widespread electric vehicle usage.
This article was written in collaboration with Prescient's Lead Editor Alyssa Sleva-Horine.