3 types of rooftop solar PV systems :

GRID-TIED – These rooftop systems are primarily designed to supply the generated power to the grid and also power the load. These systems will NOT generate power during a power failure as the inverter shuts down the system to stop sending power into the grid and avoids the risk of electrocuting utility personnel who are working to repair the grid.
GRID-INTERACTIVE – This system works in conjunction with either a battery backup or diesel generator to support the load even during a power failure.
OFF-GRID – This system does not work with the grid and is designed to work only with a battery backup or diesel generator in off-grid applications.

The difference between the systems lies in the kind of inverter used, and the inclusion of batteries.

So what are the benefits of having a greed interactive rooftop solar PV systems with battery system back-up?

You will be prepared for anything with solar battery system. It can help you keep the lights on and fridge cold in a power outage or natural disaster while potentially saving you even more on your monthly utility bills.

Your battery system will provide your home with power if the utility grid goes down—such as after an earthquake or other natural disasters. A fully charged battery provides enough energy for your essential needs during an emergency.

An additional benefit of energy storage is to reduce peak-usage charges on your electricity bill. Some utilities offer Time-of-Use (TOU) rate plans in which the price of electricity varies based on the hour of the day. Rates are higher during the afternoon when electric demand is at its “peak” across all utility customers.

A home energy storage system may help you save more money by drawing power from your battery instead of from the grid during higher rates peak hours. You can then recharge your battery during lower rate, off-peak hours.