This is an encouraging milestone. Is it trivial at this point to figure out whether a solar home install is cost effective? ie plug in your address, your last 12 pg&e bills, and get a complete quote with a break down of time to profitability?
If you live in a reasonably sunny country, the shorthand you can use is 4.5*(system size in KW), which equals the daily number of kWh your system will produce. Say that number is 30kWh. Then multiply 30 by your per kWh electricity costs. Say $0.2*30. That's your daily savings estimate, $6. Then you can figure out how many years to ROI by comparing it to the system cost. This approach will be more or less accurate if you have a battery or a nice net metering arrangement. It will be less accurate without either of these things.
Is it assuming I already have a huge battery or net metering?