Solar and backup are different jobs.
A typical grid-connected solar system shuts down when the grid loses power. Keeping selected circuits powered through an outage requires a compatible system designed for backup. Panels on the roof do not, by themselves, establish that capability.
Make an essentials list.
Before comparing storage options, list the things you want to keep operating. Separate essentials from conveniences. Bring the list to a qualified professional and ask how the equipment’s power and energy limits relate to those needs.
Ask about the whole setup.
Have the proposal explain what can run together, how long it might run under stated conditions, and how the system changes modes. Ask what happens when stored energy runs low and what you will need to do during an outage.
Further reading: DOE: The Road to Resilience with Rooftop Solar. General education; project-specific answers depend on your home and agreement.
