Off Grid Solar Systems are applicable in situations where no grid connection is available. Off grid means you are independent of the national grid, an alternative power supply can be in the form of generators or a solar system.
Due to high costs of fuel and the logistical challenges related to getting fuel to these remote locations, an off grid solar system is by far the most economical and effective solution. In addition, the silent operation of the system as opposed to the constant noise of the generator is a huge benefit.
Generators are still used in an off grid solar system but in a far smaller capacity, predominately for backup. In cases where there are several days of bad weather, the solar may fail to fully charge the batteries, or if there is a larger than factored power demand.