Just a guess - batteries to store energy from the solar panels?
But the POCO does not allow line side taps. It would have to be after the main breaker and so it would really be easier to install a small relay and shed the solar circuit while under generator power. I just dont know enough about solar inverters to understand their full capabilities. How would you live off grid with solar if you did not have a generator for backup? It would seem neccessary to have one for nightime and sunless days.