This type of plant is a mixture of both On-grid & Off-grid plant i.e. it works in 3 ways.
This type of plant is used where electricity goes off for 2-3 hours in daytime & customer also wants to save huge electricity bills.
In this type of solar system, solar panel generates energy which goes to running load in daytime from P.C.U / solar Inverter. Whatever energy is left goes to battery for charging. In case the battery is charged, then whatever energy is saved goes to government through net metering.
This type of system is a little costly than Off-grid Power Plant because P.C.U. is costly.
This type of system cannot exceed the total sanctioned load of custom (same as On-grid.)