Grid-connected PV system
Mainly, there are two types of selling / buying electricity to electricity to public Utility company in the grid-connected PV system. One is to sell the electricity via feed-in meter generated by the PV
system, then the public Utility company provides electricity to electrical appliance via consumption meter.

The other is to sell the redundant electricity generated by the PV system back to the public Utility company and vice versa.

Stand-alone PV system
The electricity generated form the solar modules will be saved into the batteries through solar charger. The Inverter will convert the DC to AC and feed into the device connected. Sand-alone PV system mainly apply in remote residence, roadside emergency telephones, r emote sensor...etc, where the public Utility can not reach.

Hybrid PV system
Hybrid PV system is combination of grid-connected type and stand-alone one. In normal operation, it behaves as grid-connected type but also charge batteries. Once there is Utility fault occurred, the batteries will discharge immediately to provide electricity to those appliances till Utility recovers.