Why Drive Electric Vehicles?

Zachary Fromm, Board Member, Winneshiek Energy District

What is the range of electric vehicles compared to vehicles with conventional internal combustion engines?

The range of Electric Vehicles (EVs) is difficult to measure because you are not dealing with gallons of gasoline; you are dealing with kilowatt hours (kWh) of electricity. The question is the same, however: How far can I drive on a full tank of … electrons vs. gasoline?

Here’s the rule of thumb I follow: You must first identify how large the battery pack is in your EV. Battery packs are measured in terms of kilowatt-hours of capacity. I drive a Tesla Model Y Performance model, which has a 75 kWh battery. Over my first two months of ownership, I have gotten 3.3 – 3.75 miles per kilowatt hour (kWh) or 248-280 miles on a full charge of my 75 kWh capacity battery.

This real-world range is less than the 303 miles of range touted on the Tesla website for the Model Y Performance (MYP) model. Experience has taught me that these are unrealistic numbers. Drivers of cars with internal combustion engines (ICE) have had similar experiences. That is, they learned pretty quickly that their real-world fuel economy wound up being less than the official EPA estimates printed in bold, oversized font on the sticker of their new car.

There are a number of factors that can determine differences in the range of an EV. These include how you drive (quick vs gradual acceleration), whether the terrain is hilly or flat, and weather conditions (cold, ice, rain). Tire types and conditions matter as well. Currently, I have 21” rims on my Tesla MYP and I know I’m losing 5-10% of range right off the top compared to 19-20” rims. These factors impact the fuel economy of gasoline-fueled vehicles as well.

What’s the cost of fueling an electric vehicle compared to a conventional car?

Our family lives in the picturesque town of Bluffton, which is exactly 13.1 miles from the heart of downtown Decorah. Every day, my wife and I commute to town in separate vehicles, and often we make that commute more than once to drive our 3 young children to various activities. In addition to the Tesla MYP, we have a 2007 Chevrolet Suburban and a slightly newer Chrysler Town and Country minivan that is a little more fuel efficient than the Suburban. Prior to getting the Tesla MYP, I think we were putting about 900 miles per month on each of the two cars. Assuming 17 miles per gallon (MPG) as an average for the two vehicles, that means we were burning about 53 gallons of gasoline each month and, at $4 per gallon, spending about $212 per month, per vehicle. Yikes!

Now let’s compare the cost to drive the same number of miles in our Tesla MYP. Our electric utility is MiEnergy Cooperative and they have an electric vehicle charging rate. We pay a higher cost to charge our EV during peak periods (9 am to 9 pm M-F) and a lower price to charge during off-peak periods (9 pm – 9 am and weekends). We have an EV charger at home that we have programmed so that it only charges our EV after 9 pm at the off-peak charging rate of $.049 per kWh. There is also a daily basic service charge for the EV charging rate of 27 cents per day.

Given my experience of getting 3.3 miles/kWh, that means I need to buy ~273 kWh per month to drive 900 miles. At $.049 per kWh, it costs me $13.38 to buy enough electricity to drive 900 miles. Then I need to add in about $8.24 in daily service charges for the EV charging rate. My total cost is about $21.61 to drive my Tesla 900 miles each month using strictly my home charger. Compare that to the $212 in monthly gasoline purchases for either our Suburban or minivan. It is costing us nearly ten times less to fuel up our Tesla! That’s a savings of almost $200 per month per vehicle at $4 per gallon for gas. (I’m going to need more solar panels installed on my house to generate the additional electricity consumed by our Tesla, but that’s a topic for another newsletter.)

Charging Options – Home and Over-the-Road

By now you are probably ready to trade in your old car for an EV! If so, the reality is that you will “fill up” at home the vast majority of the time. I just installed two “gas pumps” in my garage. For $600 I had a local electrician install two 220-volt (Nema 14-50, 50 amp) EV charging ports in between our garage doors. This way we have a convenient way to plug in every time we get home with the Tesla. As a result, we “fill up” or “top off” daily. A happy electric vehicle is a fully-charged electric vehicle. With the Nema 14-50 plug and adapter I get about 35 miles/hour charge and a full charge if I charge overnight during “off-peak” hours, which I can schedule through the Tesla app.

While all EVs can be charged via a standard (Level 1) 110-volt outlet, you will only get about 4-5 miles/hour as it charges. That means the 75 kWh battery in my Tesla would not be fully recharged if I plugged it in on empty and tried to drive it 8 hours later. That’s why investing in a Level 2 charger like the 220-volt system we have at home is such a worthwhile investment on the front-end of purchasing an EV.

My wife recently returned from a trip to the Des Moines area and I needed about 9 hours to charge from 19% of battery capacity to 100% capacity. This home charge cost me $2.43. She charged up twice on her trip (once each way) and the total at the Tesla Superchargers was $37 based on a cost of $.38/kWh. Stephanie enjoyed having the Tesla tell her where to stop and for how long to charge, which took the dreaded “range anxiety” out of the equation.

The infrastructure for charging stations nationwide is being laid right now and Tesla, without a doubt, has an amazing network of what are called Superchargers or Level 3 chargers. These chargers can fill your vehicle from 20% to 80% capacity in as little as 15 minutes (my wife did it on the north side of Des Moines just the other day) and can fill you completely up from 10%-100% in under an hour.

Thankfully, Decorah has had the foresight of installing some Level 2 chargers around town. These systems can charge at a rate of 18-28 miles per hour depending on the amperage rating. There are dual-port charging pedestals in the Luther Library parking lot, at the Fairfield Inn, and behind the Oneota Co-op on Day Spring Lane. Two more dual-port charging stations will be installed soon near the Legends Fitness Center at Luther and close to Fareway on State Street. These Level 2 charging stations are operated on a “pay-as-you-go” basis though different charging rates apply since the owner of the station gets to set the rate. You just need an app on your phone to access the charging station. Instructions are available at each charging station. Currently, there are no Level 3 (DC or Supercharger) options in Decorah, but I’m hopeful we’ll get a couple soon!

In closing

By now, I think my passion for electric vehicles is readily apparent. I believe in the future of the automotive industry and just how much this transition to EVs will have a positive impact on our air and climate. The transportation industry is one of the largest sources of greenhouse gas emissions in the United States. Electric vehicles will reduce those emissions enormously over time. I would love to elaborate on the future of battery technology and the likelihood that battery cells will become 90+% recyclable (like lead-acid batteries), but feel I’ve covered enough ground for now. Feel free to reach out if you would like to discuss more the benefits of owning an EV – I’d be happy to chat.




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