There is no free ride. I googled how much it costs to charge a Tesla...$22.00 for about 250 miles worth or near 9 cents a mile. By comparison, my eco-boost Expedition gets 650 miles on $65.00 worth of gas, or 10 cents per mile. The production of and distribution of electricity is not as efficient as many would presume.
Nah, the Tesla S long range has a mathematically accommodating battery pack of 100 KWh. At the national residential average of 12.7 c ents per KWh, that’s $12.70 to fully charge.
Even IF we reduce the stated range of 384 miles to your 250 miles, that’s closer to 4 pennies a mile.