In this paper, for further popularizing PV systems, we propose to network and control plural dispersed PV systems in small-scale area aiming to operate them against unstable weather and the complicated variation of load power. We investigate some system operation modes that enable us to realize their low dependence on commercial supply or economical benefits as added values. As for the system design approach, we examine the relation between the battery capacity and the degree of dependence on the commercial supply by computational simulation. We also consider the voltage regulation as a problem to be settled in designing the system. Experimentally clarifying the relation between the voltage and the power flow regulations in the networked system, we investigate the storage battery ability to be required for relaxation of voltage regulation.