On grid hybrid also known as grid tie with battery backup allows you to add battery backup with on grid system. You can set preference to solar or grid as per your requirement. Setting the solar to preference will allow you to use solar energy in solar hours as well as backup (from batteries) at night. Energy from grid will only be used when the power from batteries (charged by solar) has been utilized and the solar hours are finished. Setting the grid to preference will allow you to use grid electricity while you can shift to solar in outage hours (in case of load shedding) in day time (solar hours) and to batteries at night. Batteries can be charged by both solar and grid electricity.
On Grid Hybrid is a system which can store energy in itself, given the increasing demand of the solar panel system, it is noted that battery powered setup has become a need in Pakistan recently. Due to the high increase in electricity bills unit and taxes and relatively low supply had made problems. So a hybrid system helps you storing your own electricity for the time of distress. People living in developed countries like USA and UK are also moving towards solar and green energy which are relatively cheaper and a good substitute.
This system is one of the best systems out there to be used, yes it will cost you a bit more than the others given the extra things that you need, but it will also allow you to switch between WAPDA and Solar at any time you want. Imagine if there is monsoon season going on, and it has been raining for 2 days. Two things you have to think about will be that either you will have more power in the storage which is dangerous and can lead to an explosion or you do not have a reserve at all and will be forced to use electricity from WAPDA.