10 panels can generate somewhere between 300 - 400 kW depending on the roof's orientation and the time of year. For the different So. Cal. utilities, this can pay for an electric bill of up to $100.

And what does 300 to 400 kw power ???

300 to 400 kW / month is very roughly equal to the amount of appliances you can run on a $100 electric bill. It's really the size of your electric bill that determines the size of the system you should consider and how much you can save by going solar. It's also good to remember that electric rates have climbed 42% in just the last decade, so the amount of money you'll be saving with solar will only increase over time.