One of the arguments I’ve heard against driving an electric car is that coal is used to produce electricity. The argument continues that since coal produces more carbon dioxide (CO2) emissions than gasoline then it’s better to just drive a regular gas car.
The problem with that logic is that no power grid in Canada is fed purely by a coal-fired supply. In New Brunswick, where we live, about 60% of the power is generated from low or non-emitting sources. In the province with the dirtiest grid, Saskatchewan, 20% of the power is from low or non-emitting sources. In Quebec, the province with the cleanest grid, over 99% of the grid is powered from hydro.
Let’s compare the emissions produced from driving 100 km in a fairly efficient gas car (7 L/100 km) to driving our electric Leaf.
For the gas car the calculation is pretty simple. According to the USA EPA, when a car burns 3.8 L of gasoline it produces about 9 kg of CO2. Based on a fuel economy of 7 L/100 km a gas car produces about 16 kg of CO2 every 100 km.
For the electric car we first need to figure out the emissions produced when power is generated. The power companies mix of generation types (see references below) and IIPC emission figures are all we need for calculating CO2 emissions for each province. Here are the emissions, on average, for 1 kWh of power generation in three provinces:
I chose these three provinces because Saskatchewan had the dirtiest grid in 2015, New Brunswick is where we live and Quebec has the cleanest power in Canada.
Next we need to calculate the amount of power which must be generated to charge the Leaf. On average our Leaf reported traveling 6.4 km per kWh. After adjusting for grid losses (18%) and Leaf charger efficiency (90%), the amount of power which needs to be generated to send our Leaf 100 km is 21 kWh.
To calculate the emissions produced for a 100 km trip we just multiply 21 kWh by the average emission rate for each province. The emissions amount for the gas car are included for comparison.
So! Even using the dirtiest power, driving the Leaf would produce only 70% of emissions produced by the gas car! In Quebec it’s over 30 times cleaner! Using an electric car is much cleaner than a gas car in any province; in addition, it will continue to get even better as power grids continue to clean up.
So when are you going electric?
- New Brunswick power generation: 17% hydro, 30% nuclear, 19% coal, 3% oil, 12% wind, 16% natural gas and 2% biomass. From NB Power 2014-2015 Annual report
- Saskatchewan power generation: 42% coal, 34% natural gas, 14% hydro, 3% renewable, 4% coal with carbon capture, 3% wind and 3% other. From SaskPower
- Quebec power generation: 95.5 hydro, 3.0% wind, 0.8% other renewable, 0.5% nuclear, and 0.2% coal/oil/gas. From HydroQuebec