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 articles on the atom, electric current and Units of Power and How They are Related to Electricity. but if you haven’t, no worries. You can skip them and just see our final calculations below.
Here’s a brief overview for those who didn’t read the articles mentioned above.
- Electrons are subatomic particles (one of the entities within an atom) that travel through the wire when power is applied (the wire is attached to an electrical socket). This is known as electrical current and is referred to in units of amps. More on this here.
- Voltage is the force that pushes the electrons through the wire. Similar to turning on the pressure of a water faucet.
- Current usually flows through a copper wire which is the conductor and the wire is covered by an insulator (rubber packaging around the wire so that the copper is not bear).
- Resistance is the opposition to the current (electrons) that is flowing in an electrical circuit. Think of it as the friction that brushes along the side of the current.
- A watt is the energy (power) that runs the electric device. It is a product of how much electrical current is running and how much voltage (push) is occurring. It is determined by multiplying the voltage times the current. The formula is E=IR (E=voltage, I=current, and R=resistance).
- A kilowatt is 1000 watts (kW).
- A kilowatt-hour (kWh) equates to 1kw that runs a device for 1 hour.
Example: If you run an air conditioner for one hour and that air conditioner uses 70 kilowatts of electricity per hour, then you have used 70 kilowatts of electrical energy for that hour. If you run the air conditioner for two hours, you would have used up 140 kilowatts of energy.
Most EVs, with the exception of the high-end luxury ones, have batteries that consist of a 60-65kWh capacity. 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. 80% of a 65kWh battery equates to about 230 miles.
How Does 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.
For EVs, we calculate 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.
As mentioned, the industry standard for charging a 65kWh EV to 80% is about 230 miles. 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 this car as of this writing is $81.00.
- To charge a 2020 Kia Niro’s battery to 80%, the car can go about 230 miles without having to recharge.
Cost of Charging an EV
We need to add the cost of electrical use in the home, and for this example, we will use the costs from PSEG of Long Island (PSEGLI), New York, which powers Nassau County where the offices of Howard Fensterman are located.
Electrical power companies charge per kWh, so this is how we will proceed to determine how much it costs to charge your EV at home.
As the expression goes “If you read it on the Internet, it must be true!“. Well, we read it on the Internet and we got electrical costs ranging from 14 cents all the way up to 22 cents/kWh.
Then we decided to do something smart. Why not call PSEGLI directly? So we did. The information we were given was adequately explained along with a booklet they sent us that breaks down all the costs.
Understanding Your Electric Bill
The specific electrical costs are determined via the location where you reside and the electric utility plan that you have. While the brochure explains how the costs are calculated, it is recommended that you refer to your specific electric bill to determine the precise amount of your electrical costs.
Below you will find the bill in part from a home in Nassau County, New York.
The Components of Calculating Electrical Costs
Note: As mentioned, we are using Nassau County, New York as our example. Other locations may vary. We recommend you contact your local electric utility company for specific pricing.
There are two components: (Refer to the brochure which explains in detail why and how they are calculated)
- Delivery Charge: We will use the higher price listed, which is .1152 dollars or 1152 cents per kWh.
- Supply Charge: .130715 dollars or 130715 cents per kWh.
- Taxes (To keep things simple, we will not include the taxes paid in the calculation)
The electrical cost to charge an EV from the home is 14.227 cents (1152 cents + 130715 cents) per kWh. 14 cents rounded off.
To calculate the costs to charge a 65kWh vehicle to 100%, we do the following.
- Calculate the delivery charge: $.1152 * 65 kWh = $7.488
- Calculate the supply charge: $.130715 * 65kWh = $8.4965
The total cost for charging a 65kW battery to full capacity from the home is about $15.9844
But, we are only charging this device (your EV) to 80% of the 65kWh, so that results in $15.9844 * .80 = $12.78758 or $13 rounded off.
To charge a 65kWh EV to 80% capacity, 230 miles, costs $13 from a home level 2 charger.
Note: It can take up to four hours to charge an EV using a 220-volt level 2 charger.
Most electric utility companies provide more than one plan that you can select for your household. Besides the default plan which provides a standard price for electric consumption throughout the day and night, there is a plan that can allow you to select lower rates at different times of the day.
This plan, called Time of Use (TOU) is available at PSEGLI and many other utility companies nationwide. Refer to our brochure as to exactly how this works.
We will now take this cost of $13 and compare it to filling a gas tank of a conventional car that equates to the same mileage (230 miles).
Here are the steps:
- Divide the total mileage to charge the battery to 80% 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 a 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.
Using an average of today’s gas prices ($5.00 as of today), it would cost a gas car $38.7 to go 230 miles of highway driving and an EV car would cost $13 to go the same distance (230 miles) in Nassau County, New York.
That’s a savings of $25.7 for every 230 miles you drive for a typical EV in Nassau County, NY for a gas price of $5.00 per gallon.
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.
Finally, we leave you with this. Below is a copy of the estimated charges that accrued for the month of July 2022, from a 1,100-square-foot home that has an EV in its garage in Nassau County, NY. The family charges the car to its 80% capacity about three – four times per month. Notice that the cost in the Electronics category is only 10% of the total usage in the house. Something to think about!