Folks often ask “How much does an electric car increase your electric bill, and how much do you save on gasoline, per month?” Two folks interested in my Tesla Model 3 recently asked me that, and I wanted to be able to give them a better answer.
So, for me:
- Electric bill increase: $55
- Gasoline cost not spent: $277
How did I calculate those numbers?
I looked at my PG&E “hour by hour” usage for October, and then settled on Thursday Oct 25, which seemed like a pretty typical, mild Autumn day. Overnight low was 57 F and the high was 75 F. So we didn’t use too much energy for heating, and probably none for air conditioning. Our house has four folks living in it, and we have the “EV-A” plan which is a time-of-use plan. What that means is we pay less for electricity at night, and more at partial peak times, and even more at peak times. Overnight, we pay $0.13 per kWh.
The car is programmed to begin charging at 1AM, and so I can easily identify the usage spike associated with its charge.
That day’s electric usage was $8.83 total, with $2.50 attributable to overnight charging.
Our home is in San Jose, and my son drives to UC Santa cruz on a pretty much daily basis. A round trip of 59 miles, and I figured 22 days a month. On days he doesn’t drive that trip, we’d have hardly any EV charging.
So, 22 days * $2.50 = $55 total monthly electric impact.
In this real world example, if he wasn’t driving the EV, he’d be driving our 2008 Honda Odyssey minivan. It gets 17.5mpg. So:
- 22 days * 59 miles = 1298 miles
- 1298 miles / 17.5 = 74 gallons
- 74 gallons * $3.75 (our local Chevron credit card price) = $277
Full Disclaimer: Yes, this usage information is actually calculated for our 2013 Nissan Leaf, rather than our new Model 3. Kid does NOT get to drive the coolest newest car. We're a two electric car household, but we currently only have one EV charger at home, and it's a lot easier for me to charge the Model 3 at my work office than it is for him to charge the Leaf at UC Santa Cruz. So our PGE EV usage is still based on one car, and the Leaf and the Model 3 are pretty comparable in their usage. The leaf is a little better in stop-and-go urban warrior traffic. The Tesla is better at freeway speeds greater than 65 mph.
This was written by Reddit user bjm00se and posted to pureTesla.com with permission. You can view the original post here.