Equivalent Volt and Leaf Pollution Mileage in Various California Utility Districts

Electric cars do not run on manufacturers mpg ratings, nor on the mysterious EPA mpg ratings.  They run on electricity provided mostly at night provided by your local utility.  We give here the amount of CO2 produced per kWh from the US average, the California average, and the main California utilities.  For each electric car’s efficiency in getting miles out of a kWh, we translate the amount of CO2 produced in each utility to each mile traveled in an electric car. Then we can divide by the 20 pounds of CO2 produced by a gallon of gas, to get the equivalent mpg of an electric car in terms of the CO2 produced.

If you go to buy an electric car, however, you just find one EPA mpg posting.  Combined is for the mix of city and highway driving.  For the 2016 models, they are:

Nissan Leaf:  30 kWh battery, 112 mpg combined;  24 kWh battery, 114 mpg

Tesla Model X 90 D:  92 mpg combined

Chevy Volt:  Electricity 106 mpg combined; Regular Gas, 42 mpg combined

Ford Fusion:  Electric plus gas 88 mpg;  Gas 38 mpg.

We start with the CO2 produced for 1000 kWh by burning natural gas at 34% efficiency in a typical natural gas plant.  Natural gas produces 399 pounds of CO2 for 1000 kWh if burned at 100% efficiency.  If burned at 1/3 efficiency, we need to burn 3 times the natural gas producing three times the 399 pounds CO2, or about 1200 lbs CO2 for 1000 kWh.  More precisely, it is 1.17 lbs CO2 per kWh.

In the previous article on California utilities, the standard scale 1 was for CO2 pollution from natural gas at 34% efficiency.  The Total for each utility just has to be scaled up by 1.17 lbs CO2 per kWh to give the lbs CO2 per kWh of that utility.  We will give a table of those values.

Over 72,000 Nissan Leafs have been sold in the US.  In 2014, 30,000 were sold in the US.

The Nissan Leaf has a 24 kWh battery with an 84 mile range.  That gives 0.286 kWh per mile or 28.6 kWh per 100 miles.  The reverse is 3.50 miles per kWh.  There is also a 30 kWh battery with a 107 mile range.  That gives 0.280 kWh per mile or 28.0 kWh per 100 miles.  The reverse is 3.57 miles per kWh.  We use this slightly more efficient model in the table.

In the table we keep separate the unspecified power until the mpg columns, where we just add in the undetermined power as if it were natural gas power.  We round off to the nearest 5 mpg, considering the large undetermined power in some utilities.