According to google, the average US household uses around 10-12 MWh / year, and the average EV uses less than 1 MWh / year. Even if every household added an EV, that would increase electricity usage less than 10%. Not only that, but EV chargers have very good support for charging off-peak, and the grid is necessarily sized to peak usage, not average or off-peak usage, so that should have little effect.
Add to that the V2G chargers that are coming online that can actually be used just like home batteries to peak shave, and the obvious additional incentive that they add to install solar panels, and it's very easy (IMO) to come to the exact opposite conclusion that large-scale use of electric vehicle could drastically improve reliability of the grid and decrease costs.
"Figures don't lie, but liars sure can figure". No I'm not calling you a liar, it's just you fell right in a trap. You can't take the numbers and correlate them the way you've outlined. I'm not sure where your numbers are coming from, but there appear to be a whole lot of baked in assumptions, and I call the 1MWh/yr number completely bogus, though 10-12 is probably close.
First, the EV problem is not about total electrical consumption, it's about DEMAND, but lets ignore that for a moment. I have two EV's, and at the moment, I'm 100% running off solar, and I track all this crap. I use 10-12MWh in June,July,Aug without the EV. I suppose a "household" that is a cabin, or small town in rural Kentucky supporting a few small appliances and lighting, not so much usage, probably closer to 4-5MHW/year.
So I bought an EV, I loved it! so, then another. I put around 40-50KWH a week in each, call it 400KWH/mo x 12 = 4.8MWH/year for 2. I have SMALL EV's. they average 4 mi/kwh. Buy a Rivian, drive it modestly as I do, that number doubles, so I have no idea where your getting 1MWh/yr, but I call BS, no way it's that low, unless you don't actually drive it. 12000 mi / 4mi/kwh = 3000KWH = 3MWH. 4mi/kwh is REALLY good, I drive with and egg on the pedal, and coast/regen whenever possible, mostly urban driving. There is a 10% loss getting the power into the vehicle so probably closer to 3.5MWH for an "average" EV that gets 4.0. A Rivian or a Ford Lightning gets 2.3ish, that's going to double into the 7MWH/year range for a single vehicle. Generously I'll call it 10MHW for an average household with 2 cars that go 12000 miles / year. You just increased electricity usage closer to 100%, than 10.
But that is not where the problem lies. The real problem is DEMAND. If "every" household in Phoenix bought replaced their 2-3 cars with an EV and plugged it in pulling 32-40A (7600-9600kw) at 1400 (2PM) on a 115 degree day the grid would shut down completely. Phoenix actually has a very robust infrastructure, we use a crap-ton of electricity between 1400-1700 every day, but you would basically over TRIPLE demand, and nobody built out for that. Ok then, lets charge them all at night, nice, now we've only DOUBLED demand. (Still Ka-pow).
But wait, ... I'm in an urban area, that already has astronomical demand during peaks. Let's go out to the farmhouse in rural KY, or maybe a small town in Carolina with modest electrical demands. Houses are currently heated with NG or Propane, maybe a wood stove. Gas HWH's , Minimal electric use, lighting, a fridge, maybe a window unit, in a town of 5000 "households", the average "household" might peak at 30A for a few minutes a day, average usage is probably less than 1/2A (1200W). Now let's throw 5000+ EV's at their grid, all wanting to gobble 32-40A each overnight. Ka-Pow. Those homes don't really even have a "peak" most of the usages is typical drain, very mild demand curves. Typical demand on that grid would increase by an order of magnitude.
Don't drink the Kool-Aid. I *adore* EV's but if we try to put everyone in one in 10 years the grid is going to crumble, and contrary to what you are thinking it would have a profound effect, and have exorbitant costs to replace the infrastructure to handle it. Anyone who tells you different is blowing smoke up your butt.
I will also note, SRP here already has a "chiller" loop around downtown. During "Off-Peak" in the summer they crank on a few zillion AC units on roofs across downtown and start chilling water in a network of underground insulated piping used by all the buildings including Chase Field for cooling during the day. It's also used to cool the "Digital Realty" data center. Off-peak will no longer be off-peak if everyone wants to charge their cars overnight. You will gobble up excess at a rate exceeding available resource.
! Yea you can get that a significant portion of the time, the car is pretty slick traveling thru the air, I've gotten over 5 for a "tank full" in the Kona, but your going to have to keep it under 50-60MPH to reliably get over 4. That being said, the model 3 is the best performing EV for mileage and range out there. Tesla has a tendancy to "hide" the efficiency numbers, in favor of keeping you informed on how far you can go before you need to plug in. I think this was a sound decision, they've done a fantastic job with their software thus far, and reducing "range anxiety". Tesla is also among the worst about inflating their efficiency numbers for real world driving, thus YMMV!
