When I looked into solar power I was told the power company required I be connected into the grid—so when they lost power so would I!
That defeats the whole purpose of solar power imho.
Getting back to your situation, there is no requirement to tie into the grid, unless you want power when there is no sun and don't have your own storage. I have some solar plus batteries and that system is not tied to the grid power which runs most things in my house (hot water, A/C, etc).
Thats easy to get around. Have commercial hooked up to a 3 position switch. Top position is commercial, middle is completely off, bottom position is from your solar system.
All they said was you had to be hooked in to the system. They never said you had to use it!