I believe the answer to this question would depend on the goal of installing PV modules and the demand that this off-grid system would deal with. If the goal is to meet the entire demand, depending on the demand profile, installing energy storage would be inevitable.

The size of the PV module and the size of energy storage system are also interdependent. You may not be able to fully charge a storage capacity if the PV module is not large enough, therefore the storage capacity would be wasted.

This paper could be helpful:

http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2500877

Hello, S.M.S. Sadati,

Thanks a lot for your opinion.

Best regards

Following

Dear M. Darabi,

Thanks a lot!!!

Best regards