Let me explain.
I said "free" in terms of you still have to pay to charge,
I am making my statements based on my personal experience, so no pushing/projecting argument here.
You said "gas savings is about 40-50%" but can you explain 40-50% out of what?
Currently installing solar system is losing money meaning you pay or borrow money to install and it takes about 8-10 years before you make net profit assuming your solar cells/panels/other systems still work (most solar cells/panels fail/degrade before advertised 25 years life)
Here is fun facts:
My Mazda CX-5 AWD gets 25, 31 mpg (city, highway) and had zero maintenance outside warranty work for 3 years other than oil changes ($36 per year), 44 k miles with original tires and battery. and I paid $33k OTD, I pay about $650 per year for auto insurance.
CX-5 has 13 gallon gas tank. Current regular in my area is $4.25, so that's $55 every two to three weeks (depending on travel distance that month)
My gas mileage does not change due to weather and did not have any panel gap, ear pain, phantom braking, did not have to get the PPF, extra mud flaps, etc no extra cost other than the vehicle cost.
So, when you compare my CX-5 with my MYP (on order) and my brother's MYP (current), I can't say EV's saving me money,
I spent 2500 on gas driving my BMW 435 the year before I got my model 3P in 2018, and I spent about 1200 on electricity to power it in 2019. My tesla cost the same to insure as the BMW so insurance was a wash.
I am not going into the "solar is a losing proposition because it might not work longer than 8-10 years argument because thats a strawman, and also not what I have personally experienced (nor anyone else who is a regular in the tesla energy subforum).
Current regular unleaded in my area (the which is what matters when I am talking about my own experiences) is $5.45 a gallon, but regular unleaded doesnt matter to me, because BMWs want premium fuel, and right now that is $5.50 to $6.00.
Any calculations I did were in 2019 when gas prices were more normal. The higher it goes, the better I am doing, since my electricity prices are "stable" with solar providing the vast majority of my electricity.
So, your calculations show it doesnt work for you. Thats fine. I am not disputing that in the slightest. What I do dispute however is someone intimating that somehow it doesnt work for me.
The cars I drive are roughly the same price, for the vehicle, as I am not comparing a 60-70k tesla to a 30k vehicle, cause thats not what "I" was, or am driving.