Home Charging Costs
Written by Larry Thompson
For home charging a simple formula is to multiply the battery capacity in kilowatt (kW) times the cost per kW hour.
For example: A Tesla Model 3 Long Range model has a driving range of 310 miles and a battery capacity of approximately 75kW. In Connecticut, using a sample residential rate of $.185, to charge a Tesla Model 3, assuming a 10% buffer is left, 75kW x $0.185 = $12.48.
Connecticut has some of the highest electricity rates in the country. A more representative average US cost is $0.10/kW to $0.12/kW.
Some local municipalities have installed free public charging stations, usually of Level 2 capacity. However most public charging stations are fee based where the fees can vary significantly. You can find the cost of each station by using the app for the charging station (e.g. www.electrifyAmerica.com) or an app that supports multiple charging stations (e.g. www.PlugShare.com)
We can compare the cost of driving a BEV to an internal combustion car as follows:
A 2020 Tesla Model 3 Long Range model has a range of 310 miles per charge. Dividing the electricity cost of $10.40 by the range of 310 miles equals an electricity cost of $0.033 cents per mile.
A 2020 BMW 3 Series gets approximately 26 city, 36 highway and 30 combined miles per gallon of gas. A gallon of premium gasoline costs approximately $3.19. Therefore $3.19 / 30 mpg equals a gasoline cost of $0.11 per mile.