Compilation / Zhang Gull
Edited / Tu Yanping
Design / Leather
Source/Cars.com, by Joe Bruzek
If I charge my electric car at home, will my meter just soar?
Consumers who intend to buy an electric car need to consider the cost of car ownership. In addition to buying a car, the future monthly charging cost also accounts for a huge proportion of the cost, after all, the battery of the electric vehicle is heavy enough in size, compared with other battery-driven products, about the size of the entire vehicle base is a behemoth.
Plugging such a "big thing" into the home to charge, it is not difficult to imagine the stimulation picture of the meter rotating to the point where it can't stop.
While it's true that electric cars have the potential to become one of the most power-hungry things in your house, don't overlook the drastic reduction in the gas budget that comes with it. In fact, how much additional electricity bill you add to charging an electric car depends on a variety of factors, and the total household electricity bill doesn't necessarily skyrocket.
To roughly estimate how much electricity bills electric vehicles will add, you first need to check the following points:
The number of miles traveled per month
Electric vehicle efficiency measured in kilowatt-hours per mile
Local cost per kWh
This is just the most basic data, and costs will still vary based on other factors. Electricity consumption is measured in kilowatt-hours, corresponding to gasoline gallons in conventional cars. If you've ever looked at a home electricity bill, you should be familiar with the unit kWh.
To get an accurate cost per kilowatt-hour, you can calculate the total electricity bill on your bill and divide it by the kilowatt-hours used. In the U.S., the final figure should be around $0.1375, or 13.75 cents/kWh, which is the last reported average of U.S. residents in December 2021, from the Energy Information Administration.
Taking into account the month-to-month changes in electricity bills or other billing changes, the same calculation can be made for several different monthly electricity bills to obtain a more accurate average.
With known energy costs, we can figure out how much it costs to charge a popular electric car like the Tesla Model Y. The model was rated by the EPA (National Environmental Protection Agency) for 100 miles (161 km) using 28 kWh, or 0.28 kWh per mile. Then multiply your consumption of 0.28 kWh per mile by the number of miles you drive per month to get the total kWh consumption.
For example, driving 1,000 miles (1,610 kilometers) per month, 0.28 kWh x 1,000 miles gets a total consumption of 280 kWh, and then multiplied by the rate of $0.1375 per kWh to give the total cost of driving 1,000 miles per month for the Tesla Model Y at $38.5.
Tesla Model Y▼
Factors that may increase monthly electricity bills
According to the U.S. Energy Information Administration, spending an additional $38.50 a month on electric vehicles would increase the average electricity bill by 33 percent.
Driving 1,000 miles (1,610 kilometers) for less than $40 does sound fine, but it may increase or decrease as miles go by, and it also depends on whether you live in an area where electricity is more expensive or cheaper. In California, the average electricity price in November 2021 was 23.76 cents/kWh, and the monthly fee would be $66.53 more if all other factors remained the same.
Less efficient electric vehicles may also cost more money to drive. A less efficient electric car like the Audi E-Tron Quattro, at 0.43 kWh per mile (Tesla Model Y is 0.28 kWh), adds $59.13 to $59.13 according to the national average, as it needs to use more electricity for the same number of miles.
This also makes cost projections even more confusing. The above example is the best case scenario to meet the EPA rated efficiency and achieve 100% charger efficiency. In reality, the efficiency of an electric vehicle will vary depending on your driving conditions (vehicle load, altitude change, temperature), just like a normal gasoline car. In addition, during the charging process, when you take power from the grid and transmit it to the battery, there will be energy loss, so you will pay more than the car actually uses.
The cost of charging the Tesla Model Y
A car owner who bought a Tesla Model Y in November 2021 and drove 2011 miles (3236 kilometers) with a total charging cost of $183.90 by the end of February 2022 paints a less optimistic but more realistic picture of the cost of charging electric vehicles.
Over those four months, he spent an average of $45.98 a month, which is close to the estimate above — but that's based on 503 miles (809 kilometers) per month, only half the mileage in the example. In reality, the cost would be more than double the estimate.
Why is there such a difference? Because this 503 miles include some of the more expensive DC fast charging (such as Tesla Supercharger) and power loss in home charging. While the occasional level 2 free charger in a retail store can save you a buck or two, this can usually only cope with some excursions.
Of the total 2011 miles traveled, about 1,300 were charged at home, costing $79.21 on electricity; while the cost of supercharge ($104.69) came from road trips — about 700 miles (1,127 kilometers), with a total of four stops at the supercharger station.
A look at the efficiency of home charging can also tell us where some costs are going. Charging efficiency is a measure of the total energy used during charging versus the amount of energy added to the battery – ideally 100% without the loss of heat or battery regulation. But according to the TeslaFi data logger that the owner uses to record all the charging processes, the charging efficiency ranges from 69% to 96% over a longer charging time.
This means that he used 672 kWh of energy to fill 547 kWh of the car's battery due to the loss of power during charging, wasting an additional 125 kWh, or $17.19 at average kWh cost.
The efficiency of dc fast charging several times is between 97% and 100%, which once again proves that it is a more effective charging method. This is not surprising, since there will always be a loss of power when converting household AC to direct current in the car to charge the battery. On the other hand, the damage to the health of the battery caused by DC fast charging also has to be carefully considered.
The cost of a DC fast charging electric vehicle
First of all, "fast charging" is faster than home charging, but the convenience is still not comparable to refueling fuel vehicles at gas stations. Some industry insiders believe that Level 2 home charging is best suited for independent owners of electric vehicles, while fast charging should be reserved for long road trips or other emergencies.
Charges for Tesla superchargers vary from location to location, and Illinois owners say they charge 30-37 cents per kilowatt hour for Tesla's 150 or 250 kilowatts of superchargers. After one use of the most expensive supercharger, the cost was $19.72 (including taxes), the battery capacity increased by 69% (from 26% to 95%), and the range increased by 235 miles in 49 minutes.
In addition to the charger itself, the charging speed depends on the surrounding weather conditions, vehicle conditions and the charging status of the battery, usually slowing down when the charging state reaches 80%.
In Illinois, Electrify America charges guests a fee of 43 cents/kWh and a fee of 31 cents/kWh for paid members; EVGo charges 22 to 29 cents based on membership; these billing rates vary from location to location.
Not all DC fast chargers are the same, as their charging power can range from 24 kW to 350 kW, and not all electric vehicles are compatible with the fastest speeds. Typically, automakers also offer limited free DC fast charging, with caps set on an annual or kWh basis.
Tesla Superchargers and fast-charging networks such as THOSE and EVGo are billed on a per-kilowatt-hour basis as much as possible, and there are also cases where they are billed by the minute according to state regulations. "We believe that per kilowatt-hour-based pricing provides a fair and consistent charging experience for electric vehicle drivers," said IDA. We are working with regulators to follow the various procedures we need to provide electric vehicle charging on a per kWh basis. ”
In the case of not being free, using a DC fast charger entirely will reduce cost savings compared to charging at home. If only supercharging is used, at $0.30 per kWh, the Model Y will cost $84 to travel 1,000 miles, compared to $39.54 at home (based on EPA comprehensive efficiency data).
Total maintenance cost ratio of electric vehicles to fuel vehicles (Draft: Axios Visuals)▼
The cost difference between electricity and gasoline
Electric cars cost less when charging at home compared to similar gasoline cars, but the additional costs associated with buying electric cars and installing home charging equipment should not be underestimated.
Although charging an electric vehicle will increase the cost of electricity visibly compared to today in the short term, in most cases, the total cost of owning an electric vehicle in the long term will be much lower than that of a fuel vehicle. The U.S. Department of Energy says that on average, the cost of driving an electric vehicle is nearly half the cost of driving a similar fuel vehicle.