Until a year ago last November my solar panels supplied all my current and I was giving some back to the power company. I oversized them a little anticipating an EV...when I got my '17 Chev Volt PHEV I skirted through the first year on accumulated surplus. This winter It cost me $25 or so a month to drive and I expect that to go back to near zero as the sun season gets here and the clouds clear.

Want to add heat pump HVAC and hot water, probably will keep with the evaporative cooler, and will have to add 6 or 8 panels. Good job on your calculations, I've just been tracking the bills;)