I think you fit the "Heavy 4 season commuter" model from one of my previous threads. Far more detail here
*:
True Total Energy Usage (4-season climates): Evidence-based Projections.
Basically, you're looking at probably about ~45% extra energy compared to its rating. I know these aren't the exact right numbers, but say a Long Range "75kWh" battery was rated to take you 310mi, and you put 18,000/year on it, that implies about 4355kWh/year. Adding in the 45%, that's about 6315kWh/year or
roughly $290/year (since most of this will be at the cheapest tier).
The main things that will impact that number will be driving style, driving conditions, whether or not you use regenerative braking, whether or not the car is parked outside, and how toasty you like the car to be in Winter. At worst it'd be about $500 by my very rough guess (assuming short hops, toasty car, parked outside in Winter).
Now,
for Superchargers, throw out any notion of it being massively cheaper than gas. People especially in California (read: most Tesla owners) think that Superchargers are priced decently compared to residential rates -- this is absolutely not the case compared to your extraordinarily cheap and opposite world tier structure at home.
Superchargers are priced per minute or per kWh depending on the area (differing laws re: utility resales). The per minute ones are almost never in your favour compared to per kWh ones. Worst of these is the "Urban Superchargers", which give you about 72kW max. This is just enough to put you in the expensive >60kW tier, but just barely. You're getting the close to the least amount of energy per minute for that tier.
The end result, verified on a few long-distance trips now, is that
you end up paying the same amount as a cheap, efficient gas car compared to Supercharging. So while it would probably be cheaper than your current vehicle, it's not the orders of magnitude that some would have you believe (especially since a quick lookup shows gas prices in Ohio are absurdly cheap).
*One addendum I'd make to the post I linked about is that I've found a good way to reduce standby losses. Seemingly, you can reduce standby losses significantly by not plugging in the car all the time (though Tesla recommends you keep it plugged in as much as you can). My guess is that being plugged in results in more frequent waking, and it'll burn about 250W while it's awake. I don't know if this works in Winter though, when the drain appears to be due to keeping the battery slightly warmer.
Are there any good estimates of how much overhead loss there is when charging at home? There’s no way you are only using 280 wh/mile if you are measuring the power used at your utility meter. You need to factor in charging efficiency, phantom drain, etc...
I would have expected that there would be more readily available info on this by now. It’s kind of annoying that EV’s get less efficient as you drive them less because they continue to use some power when parked.
There were some good numbers on here somewhere, but I only remember the rough takeaways. 75-80% for 120V/12A charging, up to 93% or so on 240V I think. The actual charging is fairly efficient, the loss is mostly in running the computers and pumps (takes ~250-300W while charging), which takes up a higher (and very significant) proportion of available power on a standard 120V outlet. Another source of loss if you park outside in cold weather would be warming the battery (it doesn't warm it much, but most of the power coming in goes to battery warming if it's too low, very roughly 50F/10C).
You might be interested in reading the post I linked above.
