Knock On Effects Of Electric Car Purchase Now Apparent

Before we bought our EV I was naturally very curious about how it would impact our electric bill and what the actual costs per mile of driving the car would be.

We’ve had the car long enough and it has been long enough since we changed our electric rate plan, and now I feel I’ve got a much better handle on what to expect.

It’s fairly easy to calculate the cost of driving this car because, as if it was a video game that tracks scores, each time you shut it down it shows you how many miles you were able to drive per kWh in that session. A session runs from boot up to shutdown, so each time you park the car you get a new score. It doesn’t track drivers or high scores though, that might be a fun thing if it did.

high-efficiencyYesterday I had reason to go to a shop on North Main St right here in Corona. I now know it is 4.97 miles away. I intentionally drove as economically as possible, using maximum energy regeneration so that I seldom touched the brakes. I managed to get the best “score” I’ve seen yet. It’s because it is almost entirely downhill from here to there.

On the trip home I detoured on a different route to a second store, it was obviously mostly uphill, I got 3.7miles per kWh on the last of 2 legs. On our current plan a middle of the night kWh of charging costs ten cents. The car wanted to charge for 50 minutes after being driven 11 miles. For convenience we’ll round up the charging time to one hour.

The charger in our car draws 3.3kW. 3.3kW x 1 hour = 3.3kWh x $0.10 = 33 cents to drive 11 miles. Thus the energy costs for driving a mile appear to be about 3 cents. Note that I used a round trip so the effects of altitude change are balanced.

As far as the electric bill goes, for the current period SCE owes us $18 so far, of course we owe them $1100 since last May when our last annual settlement took place.


That bill will continue to go down until we settle again. It seems even more certain that the combined effects of adding an electric car and switching to Time of Use billing (TOU-D in SCE talk) will definitely result in a reduced bill, despite the inevitable increase in power consumption to charge a car we never had before. Key to this result is the small amount of driving I do. We bought the car January 9th and it is March 14th now, it has 720 miles on it.

As of right now our Chevrolet Spark EV is exceeding my expectations. Happy face!