Comparing Electric Car Costs
This calculator can be used to compare the cost to drive an electric car to a vehicle that runs of gasoline, petrol, or diesel fuel. The calculator needs a total of seven inputs, including:
- Whether or not the calculator should use US Customary or Metric Units of measure
- The miles or kilometers driven each day during the weekday
- The miles or kilometers driven each day during the weekend
- The price of fuel (gasoline, petrol, diesel) per gallon or liter
- The miles per gallon or liters per one hundred kilometers for the vehicle being compared to the electric car
- The cost per kilowatt-hour for electricity
- The kilowatt-hours per one hundred miles or watt-hours per kilometer for the electric car
The calculator then provides the user with nine outputs, including:
- The number of miles or kilometers driven each year
- The gallons or liters of fuel consumed each year
- The cost per mile or kilometer to drive the vehicle fueled by gasoline, diesel, or petrol
- The total cost per year to drive the vehicle fueled by gasoline, diesel, or petrol
- The kilowatt-hours consumed by the electric vehicle annually
- The cost per mile or kilometer to drive the electric vehicle
- The total cost per year to drive the electric vehicle
- Finally, the annual savings achieved by driving an electric car
Comparing the Cost of Electric Vehicles to Gasoline Powered Cars
This calculator allows users to compare the “fuel” cost of an electric vehicle to those powered by gasoline / petrol or diesel. Most of the variables used to perform these calculators should be well known (average miles / kilometers driven) or easy to figure out (fuel or electrical efficiency). And while most drivers know the price they are paying for fuel at the pump, they may not know the cost of a kilowatt-hour. Fortunately, the electric company’s bill will almost always provide this value.
Overall Efficiency of Electric Vehicles
According to figures published by the US Department of Energy, over 77% of the electrical energy from the grid can be converted to power at the wheels of an electric car. Conventional internal combustion engines (ICE) only convert around 12 to 30% of the energy stored in gasoline to power at the wheels. This means an EV is around 2.5 to 6.4 times more efficient than an ICE. Experts are quick to point out the efficiency of the power generator must be considered as well as power line loses, which is the energy lost as electricity travels from a generating station over the power lines and across transformers. Electrical generators range from 30 to 45% efficient in converting their fuel to electrical energy and line losses average around 7% in the United States. Everything taken into consideration, the most efficient electric vehicles may still have a slight advantage over even the most fuel-efficient gasoline powered vehicles.
If EVs only have a slight advantage, then why are the fuel costs so different?
To remain profitable, power generators need to have a precise understanding of their cost to generate electricity and that translates into long-term fuel purchase agreements. Given the purchasing power of these large wholesale consumers of oil, natural gas and coal versus retail purchases of gasoline at the pump, electricity as a fuel for vehicles has an advantage over cars powered by gasoline or diesel. There is hope the expanding use of renewable sources will result in cleaner electrical energy sources too.