Save some sunshine for later
A home battery stores electricity for use at another time. Paired with solar, it may let you use more of your own generation after the sun goes down. The value depends on your usage, the battery’s usable capacity, and the rates on your electricity plan.
Storage and backup are separate questions
Having storage does not automatically mean every circuit works in a blackout. A backup design needs compatible switching equipment and a plan for the loads it will support. Ask your installer to list the circuits that will remain available.
Decide what you want to keep running
Start with the things that matter most to you. Refrigeration, a few lights, internet, or a home office may have different requirements from air conditioning or an electric vehicle. A professional should assess both total energy needs and the power required when appliances start.
Compare a battery on its own merits
Ask for the additional installed price, warranty terms, operating limits, and expected replacement considerations. Compare the solar-only proposal with the version that includes storage. Peace of mind can matter, but it deserves a clear explanation alongside the numbers.
Further reading: U.S. Department of Energy: Solar and Storage Basics. Local rules and individual circumstances vary. This guide is general information, not a quote or financial advice.