I was thinking on buying some solar panels but I wanted some real life first hand knowledge.
It really depends on your usage habits, and the size of the system installed. For instance, if I got a modest-sized solar array, then said, "Woo-hoo, now I can run the A/C all summer and electric heaters all winter!" then I might never turn the meter back.
Now for the data points. In August 2008, we had a net consumption of -214 kWh for our house (that is, the meter was turned back 214 kWh). That’s the summer, of course. In January 2008, the dead of winter, we used a net 331 kWh. Other months are between these two extremes. Over the course of a year, it balances out to about zero kWh used. But again, if we changed the size of the system only slightly, or altered our usage patterns only slightly (say, it was a very cold winter), the answers would be different.
If you want to see our bill in detail, send me an email.