I would personally use
https://pvwatts.nrel.gov/ instead.
In South Florida at least, buying solar is like going to a used car dealer they are all scummy, I had quotes at almost 5$/watt which is insane.
I am currently working with Project Solar for a 9.5kw system and I am at $2.58/watt before the 26% incentive.
The cost savings that is usually presented to you by a solar company is usually inflated(shocker). FPL for example had only increased rates by roughly 2% a year since 1994 except for this year they did jump up from .12/kwh to $.14/kwh. FPL and Duke are both going to minimum bills as well.
With all that said, I have put a sizable spreadsheet together based on the PVWatts data, 2% electricity cost rise, and a loan at a specified interest rate... based on all my estimates in 5 years my savings is $1600, 10 years 4100, 20 years 11.5k. Based on my power usage (13,000kwh/year) There is not huge amount of money to be had but they say it does improve the value if your home. If you had an EV and a larger system then there could potentially be larger savings involved.
At this point I am doing this as an experiment, but do note if you do not find a good price for your system you can wipe out the savings pretty easily.