by default grid-tied solar won't keep the lights on when the power goes out (nothing to sync to).
Indeed, but some inverters have emergency outlets where they can supply power on a dedicated circuit as long as the panel output is enough. The amount of power is limited and it can't sustain any surges so it can't run e.g. motors, but having 1500W is tons better than having 0...
I've verified that my big-ass UPS that I use for the computer can run the refrigerator and be charged from this outlet.
Indeed, but some inverters have emergency outlets where they can supply power on a dedicated circuit as long as the panel output is enough. The amount of power is limited and it can't sustain any surges so it can't run e.g. motors, but having 1500W is tons better than having 0...
I've verified that my big-ass UPS that I use for the computer can run the refrigerator and be charged from this outlet.