Sometimes, I discuss big topics with friends and family (like why Harris is more qualified to be president than Donald) but in a way that hopefully helps us connect and understand instead of argue. Other times, those conversations are about more the minutiae of life, like getting real-deal facts about the cost of charging EVs from people who drive them daily in the suburbs of “Picket Fence Americana” (that’s me 🙋🏻‍♀️). Today’s docket addresses the mystery of money when swapping gas for electricity to power us around town.

We got our second electric vehicle a few months ago, and now we never have to stop at the gas station to fill up. 🎉 When we got our first EV in 2022, I knew I'd love not hitting up the gas station, but I love it even more than I expected.

As a family now dependent on electric vehicles with two hockey players who spend a lot of time on the road for games, we get many questions about managing the nuances of driving electric cars. But one seems to rise to the top for almost everyone:

doesn't your electricity bill go way up?

Surprisingly, not really! If we had solar panels, it probably wouldn't go up at all. Our house isn't well suited for solar panels now (maybe down the road), but we don't see much increase in electricity costs from switching to EVs. And the marginal increase is far less than we used to spend on gas! The trick for us has been time-of-use energy rates.

what are time-of-use energy rates

As opposed to standard rates, which are fixed throughout the day, time-of-use (TOU) energy rates charge different prices for electricity use depending on the time of day and day of the week. You can check out this deep dive on times-of-use energy rates I shared on my blog a while back.

why TOU rates save us money with electric vehicles

We changed our electricity rate structure from fixed to TOU rates when we got our first EV. Through our utility, it is a simple sign-up process that takes just a few minutes. This change allows us to charge our cars when electricity prices are lowest (and lower than the standard fixed rates paid by most of our neighbors).

As far as I know, all EVs incorporate features to schedule charging. In other words, you plug in the car and tell it not to start drawing energy from the outlet to charge the battery until a specific time. This allows us to plug in the vehicle when available but not draw electricity to charge it until we can pay the lowest electricity rates.

This excerpt from our last electricity bill shows the rates we paid based on the peak, off-peak, and super-off-peak periods and the amount of energy we used during each window.

Our least expensive charging window, "super off-peak," is from midnight to 6:00 a.m. If one of our cars needs to be charged, we plug it in before bed. Each car is set to start charging at midnight and continue charging until it reaches 80% battery life, the optimal charge limit for daily use to preserve the battery's longevity.

Our super off-peak energy rates are less than half the standard rate, so we save considerably by charging our cars overnight instead of during the day. Because overnight charging also helps flatten the utility's load demand, charging overnight is better for the planet, too. I explained this a bit more here.

We receive a report (shown below) from our electricity provider each month showing how much energy is used daily during each TOU period. The temperature information helps us understand how much energy usage is likely related to weather changes (heat and air conditioning systems) compared to other sources of electricity drawn from our home.

back-of-the-envelope math

I did a few back-of-the-envelope calculations and comparisons using our utility bills and charges from third-party vehicle charging stations to estimate how much we pay to charge our cars monthly at home and when we take them on road trips.

On a side note: you can take electric vehicles on road trips. We have taken our EVs from Philadelphia to Boston, Maine, Pittsburgh, New Hampshire, Washington, DC, and more. Both boys play travel hockey, so we spend a lot of time on the road traveling to and from games and tournaments, and the EV charging infrastructure in the United States is growing quickly.

Back to our electricity bills… like most households, seasonal heating and air conditioning account for most of our electricity expenses. For simplicity, I didn't consider changes in electricity rates for my analysis. I compared monthly electricity bills year over year to assess the cost of energy impact of adding our second EV to the mix.

We got our first EV (a sedan) in March 2022. I don’t have old electricity bills from then, but anecdotally, we didn’t see a rise in our electricity bills (due to the change to TOU). We primarily charge the car at home and periodically charge it at public charging stations while traveling.

We have taken our first EV on several road trips. We pay about $30-$35 for roughly 280 miles of battery charge (about $0.13 per mile), which is not hugely different from what we would pay for gas. In other words, we see significant savings on “fuel” at home and similar costs on road trips when we have to pay at third-party charging stations.

We got our second EV (a large SUV) on May 31, 2024. The charts below show a spike from May to June 2024 after bringing home the car. However, we also saw increased electricity usage from May to June 2023, reflecting rising temperatures. Additionally, June 2024 was much hotter than June 2023, so a meaningful portion of the increase from May to June 2024 likely relates to changes in weather and running our air conditioning more often.

When I compared June through September to the same months of the previous year, our energy cost increased by about $50 per month without considering rate hikes. So let's assume we pay $50 monthly to charge the SUV EV at home, for simplicity's sake.

Since bringing it home, we have also driven that car on two road trips. My husband drove it about 800 miles round trip to New Hampshire and 325 miles round trip to Washington, DC. We paid $230 (about $0.26 per mile) and $30 (about $0.13 per mile) to charge that vehicle at third-party charging stations while away from home on those two trips. Paying $60 to fill a tank of gas that covers 400 mi equals about $0.14 per mile for relative consideration.

For those looking to get an EV, it’s worth noting that the SUV requires more electricity to operate, as expected, because it’s larger and heavier. Thus, the cost analysis of adding this second EV to our energy mix likely overstates the cost for an average driver who could choose a smaller, more efficient electric car.

To summarize:

1. $0 marginal electricity cost for 1st new EV: Our electricity costs didn't really change when we got our first EV because the switch to time-of-use energy offset the increases in energy used overnight. We have taken the sedan EV on road trips over the last three years, and its cost to charge per mile at third-party stations is similar to the price of gas.
2. $1,600 marginal electricity cost for 2nd new EV: The purchase of our second EV led to an increase of about $50 per month to charge at home and maybe $250 per quarter for hockey-related road trips. ($50*12 + $250*4)
3. $3,000 savings in gas: We used to pay at least $3,000 per year ($60 per tank per car at least twice a month). It was probably much higher than that, but even so, the savings are significant, and the convenience of charging at home instead of visiting the gas station is amazing!

So, back to the original question: Does switching from a gas car to an EV increase your electricity bill? Maybe a little, but it's more than offset by gas savings, even if you take periodic road trips and need to use third-party charging stations (which are often more expensive than charging at home). If you don't take long trips, primarily charge at home, and choose a sedan over an SUV, your savings will be even greater.

What other questions can I answer about EVs? I've got a couple more I get often about road trips and charging that I'll address in the future. But if you have something specific you want me to share about, I'm happy to oblige. :)

Jen