There are a number of benefits of driving an electric vehicle (EV). One is the cost savings on gas. The other is the environment. We will concentrate on the former now and will talk about the environment in a separate article.
Before we start discussing how EV costs are calculated, make sure you have read our article on electric current and Units of Power and How They are Related to Electricity. but don’t worry. We’ve already done the calculations for you.
- Electrons are the entities that run through the wire, known as electrical current, and are referred to as units of amps.
- Voltage is the force that pushes the electrons through the wire.
- The current usually flows through a copper wire which is the conductor and the wire is covered by an insulator.
- A watt is resultant energy (power) that runs the electronic device, defined by E=IR (Voltage =” current x resistance).
- A kilowatt is 1000 watts (kW).
- A kilowatt-hour (kWh) equates to 1kw that runs a device for 1 hour.
Review Example: If you run an air conditioner for one hour and that air conditioner uses 65 kilowatts of electricity per hour, then you have used 65 kilowatts of electrical energy for that hour. If you run the air conditioner for two hours, you would have used up 130 kilowatts of energy.
What Mineral Types are Installed in EV Batteries?
The raw materials that batteries use can differ depending on their chemical compositions. However, there are five battery minerals that are considered critical for Li-ion batteries:
Most EV cars, with the exception of the high-end luxury ones, have batteries that consist of a 60-65kWh battery, which means that you use about 60-65kW when driving an EV each hour. Sparing you the formula, a battery of this size will equate to about 260 miles after a full (100%) charge.
Note: Most EVs are set to charge to 80% only. Constant charging to 100% diminishes the battery’s lifetime.
How Much Do Kilowatts Equate to Electrical Costs?
Here’s the breakdown.
If we multiply 31 miles/gals * 16.2 gals, we can determine the total mileage that this car can run on a full tank of gas, which is 502 miles.
As of this writing, the price for a gallon of gas is $5.00 on average across the United States. So $5.00 * 16.2 gallons (a full tank) equals $81 to fill up.
The EV Cars
For EVs, we calculate energy units per mile instead of MPG. For this example, we will use a 2020 Kia Niro EV, which is a fully electric vehicle and contains a 65kWh battery.
The industry standard for charging a 65kWh EV to 80% is about 230 miles before you need to recharge. If you have an EV, never let it go below 30%, as you may run into trouble if you are on the road and can’t find a charging station.
Let’s review what we know so far:
- Filling up a gas tank of a 2021 Nissan Altima will take you about 502 miles without having to fill up again.
- The cost to fill up the car as of this writing is about $81.00.
- To charge a 2020 Kia Niro’s battery to 80%, the car can go about 230 miles without having to recharge.
Now Let’s Talk About the Cost of Charging an EV
We need to add the cost of electricity use in the home, and for this example, we will use the electrical costs from PSEG of Long Island, New York, which powers Nassau County where the offices of Howard Fensterman are located.
Tip: You know what they say “If you read it on the Internet, it must be true!“. Well, we read it on the Internet and got results ranging from 14 cents all the way up to 22 cents/kWh. Then we decided to do something smart. Why not call PSEGLI? So we did and lo and behold, we found that the cost to run electrical appliances in Nassau County is 6 cents/kWh!
We will use the 6 cents/kWh; thus, the cost to fully charge an EV with a 65kWh battery is:
65kWh * .06kWh = $3.09
Note: It can take up to four hours to charge an EV using a 220-volt connection.
We will now take the cost to fully charge an EV (230 miles) and compare it to filling a gas tank of a conventional car of that same mileage (230 miles).
Here are the steps:
- Divide the total mileage to fully charge the battery by the total mileage to fill a gas tank to get the percentage between the two:
230 mi / 502 mi = 45%
So 230 is 45% of 502
- Multiply this percentage by the total cost to gas up the car:
To get the cost for a conventional car to go 230 miles, we multiply the cost to fill up the gas tank ($81.00) by 45% to match the 230 miles, and that cost would be 0.45 *$85 = $38.7.
Therefore, using an average of today’s gas prices, it would cost a gas car $38.7 to go 230 miles and an EV car would cost $3.09 to go the same distance (230 miles) in Nassau County, New York.
Drilling Down the Proportions
At this point, let’s round off the $3.09 to $3.00 for simplicity’s sake, so to go 1/2 that range (115 miles), the electrical cost would be $1.50. Similarly, to go 1/4 the distance (57.2 miles), the cost would be .75.
But How Much Does It Cost to Go Five Miles?
Why are We Asking This?
Because if we know how much it costs to go one mile, we can calculate the costs for any distance the car goes at five-mile intervals!
We already know that it costs $39 (rounded off) to go 230 miles, so $39 is to 230 miles as X (as our unknown dollar amount) is to 5 miles. The formula is 230 * X = 39 * 5, so X = (39 * 5) / 230 and X = .85, so it cost a conventional car 85 cents to go 5 miles.
If the car (our 2021 Altima) costs $3.00 (rounded off) to go 230 miles, we use the following formula:
230 miles is to $3.00 as 5 miles is to X (the unknown cost) which equates to:
230/3 = 5/X or 230X = 15 and so X = 15/230 = 7 cents (rounded)
It cost 7 cents to go 5 miles on a 2020 Kia Niro EV.
If you travel 1000 mi/month, that would equate to $170 / month for a conventional car and ~ $40 / month for an EV car.
If you travel 750 mi/month, that would equate to $127.5 / month for a conventional car and ~ $30 / month for an EV car.
If you travel 3000 mi/month, that would equate to $510 / month for conventional cars and ~ $120 / month for an EV car.
In order to determine the savings on your car against one that you are thinking about buying, do the following:
- Look up the gas mileage of your car
- Call your electric company to find out how much your electricity runs per kWh
- Use the formula above to determine the same amount of mileage your car will go against the total kWh capacity of your future EV car
- Multiply that milage by your city’s gas costs.
If you are looking to save money on gas, EV cars are the way to go. Yes, these vehicles are more expensive than conventional gas cars, but at $5.00+ a gallon, you will be pleasantly surprised how much your savings can accumulate to.