Calculating the cost of charging an electric vehicle, at home and on the road, can be complicated. For the four out of five new-car buyers who can charge at home, often overnight, the cost per mile is virtually always cheaper than the cost of gasoline for a similar vehicle. It’s tougher for apartment dwellers, who may pay a variety of rates to companies that operate charging stations in shared parking areas. For DC fast-charging, which a driver will likely want to use on road trips that are longer than an EV’s range, prices vary, but are often roughly in line with gasoline prices.
Because of these factors, the price of a full charge can vary considerably. For a Tesla Model Y, currently the bestselling EV, it could cost as little as $9 or as much as $40, depending on whether you’re charging at home or at a far more expensive Level 3 fast-charger.
To look at best and worst cases, we picked 3 EVs that span a range: from small to large, from relatively efficient to huge and power hungry. And we looked at the highest and lowest home-charging rates, which can vary among states by a factor of almost four. Finally, we calculated the cost of DC fast-charging for a road trip.
Calculating Real Cost—It’s Complicated
Here’s a question to ponder: Do you know what you pay at home for a kilowatt-hour of electricity? Few people can answer that question without doing some research. (The average U.S. cost is now about 16 cents per kilowatt-hour; 1 kWh can move most EVs two to three miles.) EV drivers can often benefit from reduced rates from their electric utility that encourage charging when demand is lowest, say, from 11 p.m. to 6 a.m.
As for DC fast-charging for road trips, the pricing is complicated. It varies among networks, may be lower at night, and may or may not require a session fee for each charging connection. Most networks also have membership plans with a monthly fee but lower per-kWh rates.
Let’s Start with Cost per 100 Miles
To make the calculations easier and let us compare directly to similar gasoline vehicles, we looked at the cost of driving 100 miles in each EV. For home charging, we used the EPA-rated range, determined using a mix of local and highway use. For DC fast-charging, we assumed those are all highway miles and used our own highway-range tests.
Overall, home charging was always much cheaper for 100 miles than paying for gasoline in a comparable vehicle—as little as one-quarter the price. On the other hand, DC fast-charging used for road trips was generally pricier than gasoline. But very inefficient vehicles driven in places where gasoline is very expensive may still come out slightly ahead for highway charging.
Most EVs today cover the bulk of their miles using charging at home or work, so the weighted average gives EVs a decisive advantage—though this may not apply to apartment dwellers without the ability to install their own charging equipment.
(Note: We added 5 percent to the recharge energy in all our calculations to account for losses during charging.)
Best Case: 2023 Chevrolet Bolt EV
In Louisiana, for a Bolt EV, 100 miles of home charging is $2.81, and 100 miles of EVgo fast-charging is $11.82; 100 miles in a 33-mpg small SUV would cost about $10.
Sure, it’s not available for 2024, but the Chevy Bolt EV has found more than 100,000 buyers during its run—and it’s a more modern vehicle than the aged Nissan Leaf it competes with. It’s also the only one with a starting price below $30,000.
This is our most optimistic case, looking at what a relatively efficient EV costs to recharge in a state with very low electricity rates. We picked Lousiana, fractions of a cent lower than Utah, both at $0.11/kWh.
In the case of the Bolt, 100 miles is 38.6 percent of its EPA-rated range of 259 miles. That percentage of its 63-kWh battery pack is 25.5 kWh. In Louisiana, the cost of that 25.5 kWh is $2.81 in electricity to drive 100 miles, when charged at home. Compare that with a 33-mpg gasoline vehicle that would require three gallons of gasoline at the Louisiana price of $3.36 per gallon. That’s about $10, meaning 100 miles in a fairly efficient comparable gasoline vehicle is almost four times as expensive as 100 miles in that Bolt EV.
On the Road
During our 75-mph real-world highway range test, the Bolt went 220 miles, so that’s the number we’ll use. (During an unorthodox range test in California’s Death Valley, we were able to exceed the EPA’s 259-mile estimated driving range in the real world.)
Doing the same calculations, we need 30.1 kWh to cover 100 miles. GM partners with charging network EVgo, which charges a $1 session fee plus $0.36/kWh on its Pay as You Go plan. That amount of electricity will cost the driver $11.82—or nearly 20 percent more than gasoline.
Home charging is much cheaper; highway travel costs more per mile.
2023 Tesla Model Y Long Range
For a Tesla Model Y at U.S. average costs, 100 miles of home charging is $3.82, 100 miles of Supercharging fast-charging is $10 to $19; 100 miles in a 28-mpg compact SUV would cost about $13.70.
We picked the Model Y because it’s currently the bestselling electric vehicle in North America. About half the EVs on roads in the U.S. are Teslas, and the company’s compact SUV hits the sweet spot in the light-truck utility segment families have shifted to in great numbers.
This is our average case, looking at what the most popular EV in the U.S. costs to recharge at the average U.S. electricity rate of $0.16/kWh. The Model Y Long Range is EPA rated at 330 miles of range in mixed local and highway use, though EV advocates and our range tests suggest Tesla’s range estimates are optimistic.
Sticking with our methodology, that’s 30.3 percent of the 75-kWh battery, or 23.9 kWh needed. At a home electric rate of $0.16, that’s $3.82. Compare that to, say, a 28-mpg compact crossover, traveling 100 miles at the average U.S. gasoline price of $3.80. It requires 3.6 gallons, costing $13.70. Again, the EV wins by a factor of almost 4 to 1 when charged at home.
On the Road
Highway travel is a different story. The Tesla Model Y Long Range model we tested on our highway test route delivered just 220 miles. So we need 35.8 kWh to cover 100 miles. The Tesla Supercharger network has variable costs for charging, from $0.25 to $0.50 per kilowatt-hour depending on how much power the station can deliver, time of day (nights are cheaper), and where you’re located (California is often pricier).
In the best-case Supercharging scenario, the Model Y costs $9.95 at a Supercharger to travel 100 miles; in the worst case, it’s double that. Those are respectively lower and higher than the gasoline you’d use, so . . . it depends.
Home charging is much cheaper; for highway travel, it depends.
2024 GMC Hummer EV Pickup
For a GMC Hummer EV in Hawaii, 100 miles of home charging is $27.48, and 100 miles of highway fast charging is $37.11 or more; 100 miles in a Hummer gasoline vehicle at 10 mpg would cost $47.90.
The electric Hummer has already fulfilled its mission: to make EVs badass. Its off-road capabilities, four-wheel steering, and stupefying acceleration (to 60 mph in 3.3 seconds) make it the pinnacle of . . . something. Its gigantic battery pack is needed not only to provide that acceleration, but to overcome the aerodynamic drag of a vehicle the size of a small municipal building.
This is our most pessimistic case: a huge, inefficient EV recharged in a state with the highest electricity rates in the nation. That would be Hawaii, at $0.42/kWh—since only one-third of that electricity comes from the state’s abundant sun and wind. The other two-thirds comes from burning fossil fuels shipped to the islands. (Gasoline is pricey in Hawaii too, averaging almost $5 per gallon lately—though not as high as California’s $5.35.) The Hummer EV has a truly massive battery pack, with a total usable capacity of 205.0 kWh.
Covering 100 miles would use 30.4 percent of the battery capacity, or 65.4 kWh. In Hawaii, that’d run you $27.48. But what kind of gas mileage would a 4.5-ton truck shaped like a Hummer get? Let’s be generous and say 10 mpg. (Its gasoline predecessor, the Hummer H1, got 7 to 9 mpg at a relatively svelte 3.75 tons.) At Hawaii’s gas price, that would be $47.90—close to double the cost of home charging.
On the Road
The Hummer EV impressed with a 290-mile result on our 75-mph highway loop, much better than expected. To cover 100 highway miles would require about 34 percent of the 205.0-kWh battery, or 74.2 kWh.
Hawaii does have some DC fast-charging stations (although its highway speed limit statewide is also 60 mph). Rates vary from $0.49 to $0.66 per kWh, depending on time of day and location. To make the math easy, let’s call it 50 cents per kWh—so 100 highway miles would cost $37.11. And, yes, that means it’s possible to spend more than $100 filling a Hummer EV.
On gasoline, even using the same 10-mpg fuel efficiency, 100 highway miles would again cost $47.90. In this case, even pricey DC fast-charging was slightly cheaper in a hugely inefficient vehicle driven in a state where gasoline is extremely expensive.
The Hummer EV is an anomaly among EVs, though GM’s full-size EV pickups and SUVs use the same underpinnings—so it may be the extreme among huge, heavy EVs with giant batteries. On the other hand, Hawaii is an anomaly too, with very expensive gasoline. We hadn’t expected DC fast-charging to be cheaper than the Hummer’s gasoline equivalent, but it was.
John Voelcker edited Green Car Reports for nine years, publishing more than 12,000 articles on hybrids, electric cars, and other low- and zero-emission vehicles and the energy ecosystem around them. He now covers advanced auto technologies and energy policy as a reporter and analyst. His work has appeared in print, online, and radio outlets that include Wired, Popular Science, Tech Review, IEEE Spectrum, and NPR’s “All Things Considered.” He splits his time between the Catskill Mountains and New York City and still has hopes of one day becoming an international man of mystery.
Source: Motor - aranddriver.com