From what you say, my understanding is that you want to run the generator as well as the PV system in parallel. If my understanding is correct, theoretically it is possible but might become too expensive to implement for a project such as a school load. You might have to invest in a synchronising scheme where the generator and load busbars can be paralleled. The generator has to trip once the frequency / phase / voltage is out of limits, so you would also have to invest in the required protection. A more practical way would be to provide an interlock between the generator breaker and the breaker connecting the PV system to the busbars such that only one of these two can be closed at any point of time. This is to prevent accidental paralleling of the two systems. A small break before make should not cause much of a disturbance unless the loads connected are critical (such as computer systems, etc.).

From what you say, my understanding is that you want to run the generator as well as the PV system in parallel. If my understanding is correct, theoretically it is possible but might become too expensive to implement for a project such as a school load. You might have to invest in a synchronising scheme where the generator and load busbars can be paralleled. The generator has to trip once the frequency / phase / voltage is out of limits, so you would also have to invest in the required protection. A more practical way would be to provide an interlock between the generator breaker and the breaker connecting the PV system to the busbars such that only one of these two can be closed at any point of time. This is to prevent accidental paralleling of the two systems. A small break before make should not cause much of a disturbance unless the loads connected are critical (such as computer systems, etc.).

Yes. there are a number of off-grid solar/diesel operations in Australia. Ergon Energy and Horizon energy are Distributor/retailers that have provided these types of facilities but there are a number of private providers. The question, as the previous answer states, is the costs of the control circuits.

Salman Jahangir : In the scenario that you are proposing, do you keep the generator always running in a warm start state? Also, is the objective to design an overall automated UPS (uninterruptible power supply system)? such that the system automatically switches from PV power source to the Generator, without being interrupted? The reason why I am asking this is to understand how would you make the system reliable under intermittent cloud covers and very high ramp-up and ramp-down times of solar power output under such circumstances?