Buying An EV? Here Is How Your Electric Bill Will Change

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If you’re buying an EV, it is easy to predict how much electricity you will use and how much it will cost you. Here are the facts.

One myth EV advocates perpetuate is that EVs don’t use much electricity. On a forum recently, EV owners were discussing the amount of electricity they use since buying their EV. One participant who was not yet an owner posted that “EVs use a trivial amount of electricity.”

That is far from the case. In fact, those who already have efficient homes can easily see their electricity usage double when an EV is added to the household.

My 1,960 square foot home serves as a great example. My electricity provider sends me monthly updates on my usage. I’ve had an energy audit performed by my provider (free, by the way), and they verified my house was as energy efficient as it could be.

What makes my home a little unusual for New England is that I use a super-high-efficiency heat pump to warm my home for part of the winter. That reduces the amount of oil I burn, but it raises my electricity usage by about 10 to 20%. My stove and oven are also electric, further pushing my electricity usage up. Look at your own electricity bill to see your usage.


Now that you have an energy usage baseline, let’s calculate how much more electricity you will use after you new EV arrives. First, go to FuelEconomy.Gov and look up the one you are considering buying. Here, we’ll compare the all-new Chevy Bolt and Tesla P100D.

The Bolt is the most modern EV on the market, and it has the longest range of any affordable battery-electric vehicle – ever.  The Tesla P100D is the hot-rod model you hear about beating other supercars in drag races. EVs do not all have the same energy usage per mile, and why should they? Bigger, heavier, higher-performance vehicles use more power to move around. It doesn’t matter if they are electric or gas-operated.

The EPA has kindly figured out how much energy EVs use per mile, and it lists the usage in the area shown marked by the red arrows above.  As you can see, the Tesla uses much more energy than the Bolt, about 40% more (what a glutton!). Either way, the efficiency is actually quite good by comparison most mainstream cars. Just don’t compare the efficiency of a battery-electric vehicle to a car like the Prius Prime or you will be in for quite a shock.

Related – Now That Bolt Is Here, Who Buys Any Other Affordable EV?

The energy used per mile is shown as kWh/100 miles. That is pronounced kilowatt hours per 100 miles. Conveniently, your electric bill charges you by the kWh. Let’s first calculate how much electricity each EV uses. The EPA says that the average driver covers 15,000 miles per year, which is 1,250 miles per month. Your mileage may vary, of course, if you drive more or less.

– The Bolt driver uses 350 kWh per month of electricity.

– The Tesla Model S P100D driver uses 488 kWh of electricity.

Thus, if I added a Bolt to my household,  my electric bill will go from 566 kWh per month up to 916 kWh. That is a 56% increase. Were I lucky enough to add a Tesla P100D, my electricity would nearly double, to 1,054 kWh. Now that you know how much added electricity will be used it is easy to calculate what your monthly cost per mile will be. You simply need to know your electricity rate.

Mine has been about $0.20 per kWh lately (you most likely pay less). Thus, it would cost a user in my area $70 to operate the Bolt and about $98 to operate a Tesla Model S. That is without any special discounts from the electric utility, which are fairly common. Tesla owners who already have a Tesla enjoy free charging at Supercharger locations. That unlimited free charging ends January 15th for new owners, but Tesla is still throwing in a substantial monthly allotment. If a Supercharger is available where you live, bonus!

Electric vehicles are much less expensive per mile to operate than are mainstream gasoline-powered vehicles. However, they do dramatically increase your electricity bill. If you live where electricity is expensive during times like these when gasoline is relatively cheap, you may be surprised to find that hybrids can actually beat electric vehicles in cost per mile for energy.

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