Electric Car Equivalent GHG Emissions in California Utilities
Having determined the CO2 emissions per kWh for the leading California utilities, we can calculate the equivalent gasoline emissions for electric or plug in hybrid cars in the different utility areas.
Since the utilities vary widely in their emissions, we take an approximately equal power efficiency for various electric cars that is accurate to about 17%. Specifically, we take the average efficiency of electric cars to be 0.30 kWh per mile, or 0.30 +/- 0.05.
We have previously estimated for utility emissions for 2016 from their Product Content Labels:
US Avg.: 0.98 lbs CO2 / kWh
CA Avg.: 0.50 lbs CO2 / kWh assuming unspecified is half hydro and half natural gas
SCE: 0.55 lbs CO2 / kWh
PG&E: 0.16 lbs CO2 / kWh
SDG&E: 0.53 lbs CO2 / kWh
LADWP: 0.79 lbs CO2 / kWh
SMUD: 0.38 lbs CO2 / kWh
SFPUC: 0.00 pure hydro
SV: 0.59 lbs CO2 / kWh
To calculate the equivalent (lbs CO2 / mile), we multiply the these by the efficiency of the cars of (0.3 kWh / mile). We then take the reciprocal to get (miles / lbs CO2). To convert to gallons, we multiply by the standard (20 lbs CO2 / gal) of gasoline, giving (miles / gal) equivalent CO2 emission. We round off to the nearest 5 or 10 mpg. This gives:
US Avg: 65 mpg
CA Avg: 135 mpg
SCE: 120 mpg
PG&E: 420 mpg
SDG&E: 125 mpg
LADWP: 85 mpg
SMUD: 175 mpg
SFPUC: infinity mpg
SV: 115 mpg
Also, anybody who charges their electric car by excess home solar power also scores infinity mpg. If you subscribe to an all clean energy plan to charge your electric car, you also score infinity. For a plug-in hybrid, this only applies as long as you drive in the range of the charged battery without gasoline.
We see that a long of the equivalent emissions are very impressive, and even the US Average of 65 mpg equivalent exceed the highest standards ever set for automobiles. The fact that the CA average is equivalent to 135 mpg is incredible.
The kWh/mile for various electric cars or plug-in hybrids was naively calculated by dividing their battery capacity by the average mileage in mixed driving. They are: Chevy Volt 0.35; Tesla Model S 0.32; VW e-Golf 0.30; Smart Fortwo 0.30; Nissan Leaf 0.27; Prius prime 0.26; and Chevy Bolt 0.25. To convert the mpg table to a specific model, multiply o.30 and divide by one of the values above.
The way to make sure that cars are charged by Solar power in California is for companies, universities, and businesses to provide daytime charging. For places that provide such charging, they effectively double the range of electric or plug-in hybrids, and bring in more use of electric vehicles, or more customers.