Dr. Strangelove’s numbers are certainly in the ballpark. I ran the numbers using other published figures for capacity factor in Arizona, plus the average power consumed per household (about 14,000 kWh), and I get about 8kW nameplate value for a solar system to do that. That is, if everything is theoretically optimal. If you aren’t tracking the sun, don’t have a south-facing roof or your cells can’t be mounted at the optimum angle, you might need a little more. Add in a bit extra to cover the losses the panels undergo over the years. A 10 kW system would be fine, but 8 kW would be okay.

I did the math also to see what it would take to power a Tesla model 3 driving the national average of 13,500 miles, and for Arizona get about 2 kW hours nameplate capacity for a solar system dedicated just to that, assuming you are net metering and can pull power from the grid when you need it. So if you also want to charge an electric car, add anothet 2 kW.

As for whether you can fit one on your roof… if you have a south-facing side, measure the area of that roof. An 8 kW solar system uses between 45 and 54 sq meters of roof area, or about 500-600 sq ft of roof space. Don’t count the whole roof - just the south facing part, because that’s what you’d use.

Here’s some pictures of solar systems of different sizes so you can get a sense of what you need. The first house has 8 kW installed.