My wife and I have an electric car on order. Plus we have a large solar system we're upgrading. I have data on last year's performance (59% of all the power we consumed the past 365 days was free from solar, obviously much higher in the spring to early fall, lower in the winter). Not too bad for an all-electric, two-story house. I'm in the process of upgrading the solar system (from 10kW to 21kW total solar panels, form 9kW continuous inverter to 18kW, from 30kWH to 90kWH battery storage, but since I drain the batteries no more than 70%, count that as 63kWh of useable storage). I believe I'll get 90% total power free from my solar system, buying only 10% from the grid (mostly during the winter). That includes the power to charge the EV to drive ~200 miles per week at approximately 4 miles per kWh (from my panel, not from the battery which is more because that doesn't account for conversion loss).
But it works that well only because we live in optimum conditions for solar (in the south, large portion of our roof facing south at a steep pitch with no shade, metal roof so I don't have to remove the panels in a few years to replace the roof, etc.). And even with all that in my favor, it's nowhere nearly as efficient as fossil fuel use. If I could drill my own natural gas and/or oil and process them I would. The only thing solar brings to the table is I can do it myself without depending on gubment policies to make it available.
It is not free because you have to factor in all of the money you are spending. Also, you need to add all of the maintenance costs. It will take a long time for you to break even if you even do.