In this paper, we propose a method for the efficient power use in power outage. The cost is high and conversion into the other function is difficult since the terminal used in conventional home network system has a dedicated function. This method is based on home network system employed with photovoltaic system. Throughout the modularization of the terminal, the variable function and cost reduction can be achieved. Additionally the unit cost can be reduced by using the power line communication. The prototype of light-control terminal has been implemented. The experimental results with the terminal show the performance of light-control system and the possibility of the commercialization can be achieved.