Cathy I am also in Florida and I am getting quotes that are all over the place as well both in system sizing and pricing but my lowest is considerably higher than yours. Everything from $25k to $42k for ~8kWh to 14.65kWh. My current actual is likely somewhere from 12kWh to 13.41kWh. To start with you have to decide if you are looking to cover all your power or just a portion of your power. I am looking to cover all my power if possible, so it was very easy to look on my electric bill on the website and it shows total kWh for the month and even the day. Then take an average of the amounts for all your bills for a year. That gives you a solid average. This is NOT what the salespeople ask you to tell them, they all want to know how much you pay, but how much you pay doesn’t have to do w/ your consumption of power.
Then at least you know if the “sales” people know anything about what they are talking about. If someone it quoting you very low or very high, kill them from your list honestly; its not worth bothering with them. I had lots of people I have spoken to now that were totally full of it. https://pvwatts.nrel.gov/pvwatts.php also will show you how much power you will produce with the specs you were given for a quote. There is also a SAM database on the top right under other Solar tools that you may find helpful. There was a third tool I used but I am now drawing a blank on where I found it that helped with sizing based on your current usage since its not a 1:1 ratio, the derate from DC to AC its actually .8. I just memorized the calculation. So you take the AC amount you need: ie 6kW and divide by .8 (6kW/.8 = 7.5kW DC). But you can also take the watts of the panels you are quoted and multiply it times the number of panels and that you were quoted for and see if that matches what you need.
You want an average of your consumption because some months you will produce more power than you need and you will backfeed it to the grid or store to battery; and then other months you will be slightly short of power so the idea is that you come close to breaking even.
Then I also live near the Florida Solar Energy Center fsec.ucf.edu/en. I went in and talked to them and they shared with me that you should make sure whomever you are speaking to is certified with them, its surprising how many are not. The list is on their website. They also suggest trying to hook up with a co-op, this is actually why I went in to try and find out if I could get any news on a co-op coming up. https://www.solarunitedneighbors.org/florida/go-solar-in-florida/go-solar-in-a-florida-group/. Your pricing may or may not be better but you will get the wealth of knowledge from watching the entire group learn from this and there are people involved that are familiar with earlier co-ops. Turns out I work with a surprising number of people involved in a few of the past co-ops in my area and I got on Nextdoor and was able to get some details from neighbors around me too. Plenty of people want to share their monitoring sites because they are so happy.
With all this I was able to narrow down who was just a sales person and full of it and who actually knew anything about solar. I let most of the people talk themselves into a hole telling me about their commission structures, one guy told me how he was on salary. When they are on commission it is to their advantage to oversize a system because they are paid more based on the higher number of panels. But the guy on salary really knew nothing about solar. That is not who I want designing my system. Most of the companies I spoke to honestly were the ones involved w/ the co-ops. They were the ones who actually seemed to know the most about solar in the end. I also read BBB, google and yelp reviews, looked up business filings and looked at the top installers from https://www.solarpowerworldonline.com/top-solar-contractors/ list. I met with one company who I found after was trying to open under a different name, hiding from their prior complaints. That company was Sunbility, avoid them and Blue Sky, Dani Grant and Grant Solar Energy, they are all the same company. Then I had to read warranties, this was the first thing that made me very suspicious of Sunbility the guy knew nothing of the warranties; and they insisted on coming to my house especially when it was clear he had no reason to be at our house. He kept trying to write up a sale with us but he couldn’t even tell us what panels could be installed.
We have had other types of solar before and the warranty can be important in my experience. We also live on the river nearby the ocean and it turns out many of the panels have exclusions for this area. In the end the only two manufacturers that allowed coastal installations were Sunpower and LG. Many of them had surprising exclusions. This is just my experience and everyone goes into this with very different goals. About half went in trying to go solar for the cheapest price, some wanted a better system than the cheapest price gave them or better components. There are vastly different types of inverters for instance. I am happy to share the companies that I narrowed my list down to if you wish. They all seem to work in a large area of Florida. I haven’t made a final decision yet but I have narrowed things down to a few companies.
Take care and I hope some of this helps you,
Alysa