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Electric Vehicle Charging: Impacts for Electric Utilities

This is part one in a series dedicated to helping electric utilities prepare for a future with wide-spread electric vehicle (EV) usage.

Climate change is a big factor pushing our society to go all-electric. The transportation sector still has a huge transition ahead of it: electric vehicles (EVs) will replace the majority of gas-powered vehicles in the near future. Electric utilities must plan now for a future in which every residence has at least one electric vehicle.

Gas-powered vehicles offer convenience in that gas is readily available in most areas, and accessible in under 10 minutes. Unlike gas-powered cars, electric vehicles cannot be fully charged and ready to go in 10 minutes. However, there are a few ways to make it easier for EV owners to charge their cars, whether they plan to recharge at home or on the go. It is vital that electric utilities consider EV charging options, and the infrastructure that will be necessary to support it.

Let’s compare convenience factors of gas-powered and electric vehicles. We’ll also explore charging options for EVs both at home and on the go, and infrastructure updates that electric utilities will need to make to support widespread EV usage.

Convenience of Gas-Powered Cars vs. Electric Vehicles

In a typical city with 100,000 residents, there is likely to be about 40,000 residences, 60,000 automobiles and light duty trucks, 200 buses, 500 delivery vehicles, and 500 heavy duty trucks. Approximately 50 gas stations supply the necessary gasoline to keep these vehicles moving.

Today’s petroleum economy allows people to use their cars for everything from the commute to work to long distance road trips. Relatively low-cost fuel is readily available at almost any time of day. However, the cost of gas is fickle and higher prices can bar low-income people from driving frequently or going on long distance trips.

There is an ease to using gas powered cars – people can refill their gas tank in about 10 minutes at a nearby gas station almost anywhere in the US. Even when driving hundreds of miles to vacation spots, refueling for the return trip is generally possible in a short amount of time.

Though EVs lack the refueling convenience of their gas-powered counterparts, they offer some conveniences that gas-powered vehicles do not. Owners can save on fuel costs, as electricity is much cheaper than gasoline. EVs also typically require less maintenance than traditional gas-powered vehicles, which also saves the owner money. Some states even offer tax credits, rebates or other benefits to EV owners.

Expanding ownership of EVs is inevitable, especially in the face of a changing climate. Electric utilities would be wise to prepare for this future today.

Electric Vehicle Charging at Home

Electric utilities supply energy to all types of residences: single family dwellings; townhouses where two or more residences share adjoining walls; apartments and condominiums with multiple units on each floor, and more. Many EV owners will charge their vehicles at home most of the time.

Residential EV battery chargers can be designed to charge a battery in 6 to 12 hours by delivering 50 KWH in 6 hours, or 100 KWH in 12 hours. A 240 V, 200-amp residential service panel in a single-family dwelling should have the capacity to supply one 50 KWH, 6-hour charger or one 100 KWH, 12-hour charger. However, when a single-family residence has more than one EV, residents will need to coordinate charging sequences or drive to EV charging stations.

Service panels in apartments and condominiums can be 240 V, 100-amp panels that only have the capacity to supply one 50 KWH, 12-hour charger. Because of this, apartment and condominium residents will likely need to rely on commercial EV charging stations to recharge for trips and long daily commutes.

Unfortunately, many new residential areas being developed today are not planning for widespread EV usage. This lack of forethought is likely to cause issues in the near future.

EV Charging Facilities for On-The-Go Charging

Charging an electric vehicle while on the go, whether after a commute or on a long road trip, will be faster than residential charging but slower than today’s gas stations. Fast charging stations will have spots for 8 to 20 cars; fully charging one vehicle will take about 15 minutes.

The same city with 100,000 residents will need about 50 recharging facilities with the capacity to charge 8 to 20 cars at the same time. It’s reasonable to estimate that half of the charging stations can charge 8 EVs at once, and the other half can charge 20 EVs at once. This allows up to 700 EVs to be charged at any given time.

EV owners that arrive at a charging station that is at full capacity will face up to an hour of wait time, as recharging each vehicle takes at least 15 minutes. Luckily, there are several potential solutions to minimize wait times.

One option is to provide a valet service for recharging vehicles while customers shop, dine, or see a movie. Another option is to give EV owners the ability to schedule their charging time so that they can arrive at the charging station a few minutes before their scheduled time. In either method, at least one third of chargers should remain available for drive up usage.

Fast Charging Stations Will Require New Infrastructure

Commercial fast charging stations will add significantly to peak load. To meet the demand for energy required to charge an EV, each fast-charging station must be equipped with twenty 100 KWH 15-minute chargers, each of which will require a separate 12.47 KV electric energy source. When 25 charging stations are operating with 20 stalls at each station, the host utility will need to build new distribution lines to each station, 25 in all.

If charging stations are concentrated in certain areas, as many gas stations are today, new substations will need to be constructed. Host utilities will need to build one new, complete substation to provide power to four charging stations located in the same area, such as on the four corners of a large intersection.

An additional consideration that we’ll explore in a later article relates to tourist towns. Utilities in places with a strong tourism economy, such as Atlantic City Electric and Tillamook PUD, will need to build extra charging facilities based on the number of tourists during their peak season. Alternatively, with the right incentives from utilities, hotels, casinos, and resorts could invest in 6-hour chargers for tourists to use during off peak hours.

Electric Vehicles: The Future of Transportation

After reading this article, take a five mile walk around your neighborhood. Notice how many single-family homes, apartments, or townhouses you pass. Count how many gas stations, hotels, restaurants, businesses, and office buildings you see. If you have the time, walk the same route twice, once in the morning and once in the evening. Be sure to note the number of garages and cars in driveways, as well as the amount of on street and off-street parking, parking near shops and restaurants, etc.

Now imagine that 75% of all the vehicles you observed are electric vehicles. That’s 75% of cars parked near shopping areas and restaurants, outside homes, and in garages. Is your utility prepared to supply the necessary energy to support all these EVs?

If not, consider reaching out to Prescient for an assessment and suggestions to improve your utility’s EV preparedness strategies. Or follow along with this blog series! Next up, we’ll present pricing strategies to reduce our reliance on gasoline powered vehicles and increase the appeal of electric vehicles.

This article was written in collaboration with Prescient's Lead Editor Alyssa Sleva-Horine.

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