Q: What is the “fuel” efficiency of a modern electric car?
A: A typical energy usage number for an electric car is 25 kWh per 100 km (40 kWh per 100 miles) traveled. At today’s electricity and gas costs that works out to the same cost per 100 km as purchasing 2.41 liters of gasoline. 2.41 liter/100km or 117 mpg (for us old folks).
Calculation: O.K. where do the numbers come from, and what are the calculations used?
- 25 kW per 100 km. measurements on my own plug-in Prius show a consumption of about 25 kWh per 100 km. The Nissan EPA label lists the Leaf at 34 kWh per 100 miles, which equates to 21.1 kWh per 100 km (divide by 1.61 to go from 100 miles to 100 km) This 21.1 value is typical of today’s production EV’s, and is a bit less than my measured Prius value of 25 kWh/100km. So the 25 kWh/100km number is a bit conservative, and it is likely a “city miles” value obtainable by most light-footed EV drivers.
- $0.1225 per kWh from Saskatoon Light & Power – Reading from my electric bill, I am charged $0.1167 per kWh, and then charged 5% GST = bringing the cost up to $0.1225 per kWh after tax. To confuse this number a bit, you could add 2.5 cents per kWh ($0.1488 including GST) if you are purchasing “green” power from the grid, which is an option through both SaskPower and the City of Saskatoon, or you may value your energy at $0.0961/kWh ($0.1009 with GST), which is the rate the City of Saskatoon will pay for grid-tied solar or wind power. For the purpose of this posting, $0.1225/kWh is used.
- $3.06 per 100 km Multiplying the 25 kWh / 100 km by $0.1225/kWh yields the total electrical cost to travel 100 km.
- $1.269 per liter for gasoline http://www.saskatoongasprices.com lists gas prices for most major providers in Saskatoon at $1.269/liter. Consumers can likely pay up to 10% less than that when considering various discount or membership programs available.
- 2.41 liters for $3.06 – this is the amount of gasoline which could be purchased for the same amount of money spent on the electrical energy used to drive 100 km. $3.06 / $1.269 per liter = 2.41 liters.
- 2.41 liters per 100 km – based on dollar equivalence. Compared to almost all gas vehicles this is fantastic economy. 5 liter/100km is considered very good for city driving in most gas-only vehicles.
- 117 mpg – using the website: http://www.calculateme.com/cGasMileage/LitersPer100kmtoMPG-imperial.htm to convert 2.41 liter/100 km into mpg (imperial).
There are a number of contentious issues around EV’s including road taxes, range, charging stations, up-front costs and subsidies, energy production subsidies, environmental aspects, maintenance an other operating costs, etc. but these issues have been ignored for this article, and it tries to provide a comparison of the simple costs of operating a plug-in electric vehicle vs. a gas vehicle in Saskatchewan today. We look forward to any questions or comments, and please let us know if we have made any serious errors or omissions in this post.