If you’re juicing up your electric vehicle (EV) at a commercial charging station, you could be paying a lot. In fact, a recent article in the newsletter Torque News, a writer claimed that at a commercial DC fast charger (DCFC) he paid three times what it cost to fuel up his gas guzzler for the same amount of mileage—30 cents vs 12 cents per mile.

At the DCFC he paid $10.15 for 9.5 kilowatt hours (kwh) or nearly $1.07 per kwh. That’s close to ten times the rate charged by Xcel Energy to residential customers in Colorado, depending on time of day, time of year, and energy plan. And regardless of the variables, if you charge at home between 7 pm and 1 pm the following day, you pay 10¢ per kwh regardless of your plan.

MPG vs MPKwh
We’re all familiar with miles per gallon (mpg) for gasoline and diesel vehicles but when you’re “fueling up” an EV, you’re filling it with watts (in this case, thousands of watts or kilowatts). And just like conventional vehicles, EVs vary in how many miles you can go on a kilowatt hour.

Compact EVs, like the Chevrolet Bolt driven by the Torque News writer above, average around 3-4 miles per kilowatt hour. Just like gasoline-powered cars, the miles per kwh goes down with high-performance cars like the Ford Mustang E and Porsche Taycan, and heavy trucks like the Ford F-150 Lightning use even more.

Now mpg calculations are pretty simple: how many gallons of gas did you use to go a certain number of miles? The same holds true for figuring out fuel efficiency for EVs. How many miles did you go on a charge and how many kwh did you use? That’s relatively easy if you use a commercial charging station because it tells you the number of kwh you just bought (and what it cost). Figuring out how much your car used from a home charger is a little trickier since the car juice is mixed with all the other electricity you use at home. But EVs and many home chargers have apps that collect data, so you may be able to see exactly how many kwh you’re using and your mileage since the last charge. Failing that, you can look at your electric bills before and after you began home charging and get a reasonable estimate.

Where You Charge Makes a Big Difference
EV chargers are rated on three levels. Level 1 chargers can be plugged into a standard home outlet—presuming you have enough power at that location. A 15-amp circuit will only support 1,800 total watts (1.8kw) and 20 amps deliver 2,400 (2.4kw) and if there’s much of anything else on the circuit, charging a car could cause an overload. Plus, it takes a l-o-n-g time to fully charge your car with a Level 1 charger.
Level 2 chargers run on dedicated 240-volt AC circuits of 40 amps or more. They’re found both in home chargers and commercial “filling stations.” They can fully charge a typical EV in 5-12 hours making them perfect for home use overnight but only practical for partial charging at commercial stations.

Since 2016, Denver and many other locations require that all new residential construction include provisions for Level 2 EV charging stations. At minimum, residential garages and carports must have sufficient electrical conduit installed to enable 240-volt, 40-amp wiring to be easily pulled to an outlet for future EV charging stations.

But unless an EV charging option is already installed, there’s more work to do.

Level 3 DC fast chargers are the big dogs. Generally limited to commercial charging stations and other businesses, they use direct current (DC) at very high voltages to deliver lots of charge in a relatively short time. They take around 15 minutes to charge your EV to go about 30 miles.

Bottom Line: Home Charging Saves Both Time and Money
Even 15 minutes can seem like an eternity standing around a charging station, especially in bad weather. And a Level 2 station, while maybe a little cheaper, is even slower. Not to mention the fact you’ll probably pay 5-10 time more that you would at home.

Adding a home EV charging station makes sense for homeowners. It lets them charge their vehicle(s) conveniently at home, letting them use their time better and avoid the hassle and expense of using commercial charging stations. Plus, since they’ll probably be charging overnight, they’ll be buying electricity at off-peak rates instead of higher daytime prices (and without markups for overhead and profits).

Plus, it adds value to a home when it comes time to sell.

Allstar Electrical Services has installed dozens of EV charging stations in homes, parking garages, and at businesses with multiple EV fleets. We’ve helped Coloradans increase efficiency while adding comfort and convenience to their homes and businesses for over 20 years.

For an estimate on installing a home EV charger or to learn more about the many ways upgraded electric services and emerging technologies can improve your home or business, schedule an appointment our website or give us a call at 303.399.7420.