Pavel:  "  The size of your solar system is slightly more, than I would expect and with an annual production of 7MWh could indeed comfortably charge Model S, especially if you got space for some extension. "

Yup, that would convert to 6.8 MWh per year and that makes it sound like quite a lot, but as I posted on an additional post, the average 2,000 square foot home in the US uses around 1,000 kWh per month or about 12 MWh per year so I only produce  a little over half of my yearly electricity needs by my existing solar system and the rest of our needs come off the grid, just like most other home owners.  Mine is not a huge investment in solar at this point, especially since I essentially rent the equipment by paying a pre-arranged set kWh rate for all the electricity it produces, but I do think quite seriously about expanding it in the future.  It was more of a curiousity situation in the beginning and an appreciation for the science that started me in this area of home solar electricity generation. I am past that initial curiosity stage and it won't take much for me to dive into the deep end of the swimming pool in the future if I have the "discretionary funds" in that future.

It is interesting, when I think back on it, that my grandfather on my mother's side had wind generated electricity on his farm in western Oklahoma back over a hundred years ago and used lead acid batteries as his ESU facility to store the energy produced and then wires set up to his house to provide lighting and power day and night off the stored electricity in his ESU.  He was one of the first farmers in his region to electrify the farm.  In a way I am just carying on his tradition... but without the ESU... so far.  If I continue in this vein then I, too, will add ESU only it won't be lead acid batteries!

He was also one of the first in his area, if not the first, to have ICE powered tractors and a Model T Ford.  He was an early adaptor and just didn't know it.  I am far from being an early adaptor and as for not knowing it, well there is a lot that I don't know and I am constantly being reminded of that deficit.       Best regards.   Okiedo