The Criteria whether to install solar hybrid System or on grid system is yet complex and simple at a same time. We would recommend you talk to competent solar contractor before making such decision, but here are a few tips. 

On Grid System is best where there is no load shedding and you a have a 3-phase meter and your objective is none other than reducing your utility bill. For un-announced outages such as utility faults/tripping, you can always attach am existing or new UPS which will charge from on grid system and will not pose any tariff increase for you. 

For places where you have load shedding and / or you have a critical load to feed such as dispensaries, IT loads, emergency lighting or processes you must go for the hybrid system. Hybrid system will give you luxury of net metering and no outage in case of load shedding.