Today I got the first full month power bill since the solar went in. Our system pulls what it can from solar, saves extra to battery, and when the battery is empty pulls from the grid. Being this is Phoenix, in the summer, keeping the climate in our house livable is the primary power drain. It was 100F (38C) by 8:00 this morning. The silver lining of this weather is, it's sunny! Our power bill was ~$140 LESS this year than July last year. It's not 1 to 1 obviously, but I like it anyway.