Will Buying an EV Cause Our Electric Bill to Go Down?

Chevrolet_Spark_EV-14 Since we installed our solar panels in May 2012 we have been generating almost all of the electricity we use, but depending on the time of year most months we still do buy some electricity from SoCalEd (Southern California Edison).

When we bought a Chevrolet Spark EV in January 2014 we knew that it was inevitable our electricity consumption would increase, but what we did not realize was that the change in our billing plan to one designed for EV owners could result in an overall lower electricity bill.

On the TOU-D plan rates are lowest between midnight and 6AM, so we have programmed our car to charge at those times only. In the meantime, during the day, our nominal 15KW panel arrays are putting lots of power onto the grid, spinning our meter backwards, at a time of day when rates are most expensive. I always visualized the billing as KWH used minus KWH put on the grid, times rate, but apparently when we are producing excess power we are being credited for the dollar value of the power we produce, thus at the highest rate.

You can see the spike in power use before 6AM, the car will begin charging at the time it calculates is necessary to be fully charged by 6AM. The day before I must have driven a lot because the charge duration is longer than most. I chose this day to show because it was sunny, you can see we crossover from using power to producing it early in the morning, and by noon, during the most expensive rate time for our plan, we are powering several of our neighbor’s houses. Peak-Power-during-On-Peak-hours And our bill is going down quickly.

I am liking very much this buying an electric car experience, especially the car. If it means our electric bill must go even lower, c’est la vie.