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How to Calculate EV Charging Costs

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There are a number of reasons you might want to buy an electric vehicle. You might choose an EV because you care deeply about your carbon footprint, for example. You might choose an EV because you keep your vehicles for a long time, and you’re concerned about the future value of a vehicle powered by internal combustion. You might not care about any of that and may just want the quickest, stoplight to stoplight street racer you can get your hands on. Regardless of your motivations, though, the reality is that most of us have to live within some kind of budget, and understanding how much an EV will cost to buy is only one part of understanding how much your EV is really going to cost you– but the other parts? That’s not always so easy, which brings us to the handy-dandy how-to guide you’re reading now: How To Calculate EV Charging Costs.

How to Calculate EV Charging Costs 1 | Understanding the Variables

Vehicle cost calculations are often pretty basic, once you know the variables. To get a good idea of how much it might cost you to complete a given road trip in an internal-combustion vehicle, you need to know the average cost of a gallon of gas (or, God forbid, diesel) along your route, the length of the trip, and the average fuel economy (in miles per gallon) of the vehicle you’re driving.

    1. Cost of Fuel
    2. Distance Traveled
    3. Vehicle Fuel Economy

To keep things simple, let’s assume you’re driving a 2019 Volvo S60 T5 that’s rated at just over 30 MPG on the highway on a 300 mile, mostly highway road trip from Chicago, Illinois to Cleveland, Ohio, and gas costs about $3 per gallon along the way. So, to cover 300 miles in a car that’s good for 30 MPG we’ll need 10 gallons of gas. At $3 per gallon, that road trip will cost us about $30.

(300 miles/30 MPG) = 10 gallons * $3/gal. = $30

Now, sure, that’s over-simplifying things a bit. We’re not taking into account, for example, the wear and tear on the vehicle, the price of continued maintenance, tolls, or any of the other myriad little expenses that go into real accounting work. But even so, $30 is a solid, common-sense type answer to the “What’s this trip cost?” question.

Similarly, to know how much it would cost to “fill up” a gas-powered car, we’ll need to know two variables. First, we need to know how much the fuel costs. And, second, we need to know the fuel capacity of the vehicle in question– in other words, “We need to know how big the tank is.”

Let’s use the same example we used above, and assume a 2019 Volvo S60 T5 with a fuel capacity of approximately 15 gallons. At $3 per gallon, it will cost us $45 to fill up the tank from empty.

15 gallon tank * $3/gal. = $45

Those are variables and equations we can all wrap our heads around pretty easily, I think. The price of gas is somewhat tied to the price of oil, obviously, and that fluctuates a bit– but if gas costs about $3 per gallon in the morning then it’s a pretty safe bet that it will cost about $3 per gallon in the evening, too. And that, dear friends, is where calculating the costs of filling up charging your EV can start to get a little complicated.

How to Calculate EV Charging Costs 2 | the Variables are Insane

The first variable listed above is “Cost of Fuel”, and that’s– well, that’s not terribly easy to figure out when we’re talking about electricity. That’s because utility companies charge different amounts for electricity at different times. During “peak usage hours”, for example, they ratchet rates up. During “low usage hours”, electricity can be much less expensive– even free! The crew at Edmunds explains the problem wonderfully, “What if a gallon of gasoline cost $3 (per gallon) at breakfast time, was free at lunch, bumped up to $8 in the afternoon, but was only $2 in the middle of the night? Welcome to the world of charging up plug-in electric vehicles.”

So, how do we tackle this problem? One way is to use an average cost– but, instead of average cost of a gallon of gas, we’re going to be looking for the average cost of a Kilowatt hour (or, 1 kWh) of electricity.

You probably know what a gallon of gasoline is– but a kilowatt hour may be a bit less familiar. Basically, one kilowatt-hour 1,000 Watts of power sustained for a full hour. So, like, if you have a 100 Watt light bulb, and it runs for 10 hours, that’s 100 Watts * 10 hours = 1 kWh. The formula looks like this …

Wattage (100) x Hours used (10) / 1,000 = Kilowatt Hours Used (1kWh)

Now, as we said before, calculating the the cost of a kWh isn’t always easy. It’s crucial to our math, though, because an electric car’s energy consumption is measured in kilowatt-hours per 100 miles (kWh/100 miles). You can usually find that rating on an EV’s EPA Fuel Economy sticker (assuming it’s a car), or in the owner’s manual (if it’s a motorcycle, for example). If you’re buying your EV used– and there are plenty of great reasons to do that, by the way– the Department of Energy (DOE) keeps track of most vehicles’ economy ratings on its Federal fuel economy website. You can find listings for pure EVs here, and the listings for plug-in hybrids (PHEVs) over here.

So, how do we find the cost of a kWh of energy? It’s a bit different with each state and each utility company, to be honest. That’s the bad news. The good news is that you can typically get away with knowing just the average cost of a kWh of energy in your area. Using this Electricity Data Browser curated by the US Energy Information Administration, we can find that, in Illinois, the average price of a kWh of electricity is currently $0.0933.

40 kWh * $0.0933 = $3.73 per 225 miles

You read that right, kids. If we’re driving a 2019 Nissan LEAF equipped with a 40 kWh battery pack, and we live in Illinois (where energy costs about $0.0933 per kWh) it will cost us about $3.75 to “fill up” the LEAF and drive some 225 miles. If we’re making the same 300 mile drive we talked about earlier, we’ll need to stop somewhere along the way to juice up, sure, but that trip will still cost us closer to $5 than it will $30. That means the same drive in the EV will cost about a fifth of what it costs in an internal combustion car– and those savings keep on coming. You might spend $3,000 to drive that 30 MPG Volvo 30,000 miles, and pay less than $500 to drive your LEAF that far. That’s especially true if you can manage to charge up your EV during “off-peak hours“. That’s usually between the hours of 11PM and 7AM– when most people are sleeping. Heck, you’ll even save on oil changes, too!

How to Calculate EV Charging Costs 1 | What Have We Learned?

If you’ve made it this far (thank you!) I hope that you’ve learned a few basic facts EV charging costs. Sure, the costs vary and it may seem like a daunting task to really pin them down, but that shouldn’t be your big takeaway from this post.

Instead, I hope your big takeaway is this: it can be substantially cheaper to own and operate an electric vehicle than it is a comparable internal-combustion car– which should be obvious, whether you’d call a Volvo S60 T5 starting at $36,000 comparable to a $29,990 (before tax credit) Nissan LEAF or not. Heck, even at Hawaii’s nearly $0.23 per kWh cost for electricity, you can still “fill up” that Nissan LEAF for about $9 … and that is just freakin’ awesome!

If you’d like to see how much it might cost to fill up a few different EVs in your state, head on over to Enrg.io’s handy-dandy EV Charging Cost Calculator page— there’a a link at the top of our site, too– and start plugging in numbers. We’ll be doing our best, in the meantime, to make sure all the numbers are up to date and you’re getting the best information we can provide. In between working our regular 9-5s, anyway! Go check it out, then let us know if you found any cool surprises in the comments section at the bottom of the page. Enjoy!

 

Original content from Enrg.io.

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Jo Borrás
Jo has been working in the automotive industry since 1997, and has been a contributor to various automotive and technology blogs for more than a decade. You can usually find him talking about Swedish metal at his Volvo fansite, out cruising on two wheels, or chasing his kids around Oak Park, IL.