When a portion of the low-voltage distribution network, typically a village, is disconnected from the upstream network, due to a fault or maintenance, it can be reenergized temporarily by the distribution system operator. Usually, if closing of a normally open tie-switch connected to a neighboring feeder is not possible, a diesel generator is conveyed to the islanded grid portion, and used towards temporary energy supply. This solution though can be costly, environmentally detrimental or not available. In this paper, an alternative solution towards temporary energy supply of a islanded grid is presented, relying instead only on local renewable sources, here photovoltaic sources, and a small battery. This work further improves decision-making, by providing valuable information to system operator. Given consumption and generation time-series data, the continuous supply of the islanded grid is estimated, depending on several parameters such at the starting time and the demand response scheme enforced.