The first thing to consider is if you are going to buy or lease the solar system. If you buy, what is the cost and are you going to purchase a battery backup system such as the Tesla Powerwall. Then you must determine how many solar panels and their orientation on your roof. Solar panel prices are coming down, but not battery prices or installation.
If you lease the system, what will happen with the system at the end of your lease? Will you buy it, extend the lease, or have it removed? What costs can you expect for each scenario? When leasing a rooftop solar system, incentives such as tax credits and depreciation are given to the system owner, not the homeowner. If you own a home with a leased rooftop solar system, you may need to pay additional property taxes. You can't take it with you when you sell and/or move. As a homeowner, you may have a lien placed on your property if the system is leased and not owned. That could complicate things when it comes to selling your property.
When it comes to savings, remember to factor in the cost of the monthly lease payment. Focusing on only the savings on your utility bill is just half the picture. Changes to electricity rates and regulations can impact the benefits outlined or promised in your contract. Net metering is going away - Hawaii, Nevada, CA, AZ, and maybe FL. Utilities are adding a monthly charge for solar customers for access to the grid.
Power Generated. Solar systems don’t generate enough power to start large appliances like your AC unit or pool pump. Stationary panels achieve optimal power 2-3 hours per day.
Power Outages/Battery backup. The power from solar panels is designed to shut off during power outages for safety reasons. So when there’s an outage, customers with rooftop solar lose power too. Rooftop solar systems are Grid Tied, that means when the power is out, you cannot generate electricity due to utility regulations/mandate. Battery Backup (Tesla powerwall) can't be recharged from the solar panels.
Roof Problems. Have the condition of your roof checked thoroughly. What happens if you need to repair your roof? Roof damage can happen during installation, including leaks or roof instability.
This is why a Grid Eraser portable solar powered system makes the most sense.