In this paper, the authors preserve full coverage-target area while minimizing the number of active nodes. The nodes which are available in the wireless sensor networks consume more energy even when the nodes are not sensing or covering the target area. Radio energy models are being used to find the energy consumed during access of the nodes at various modes like transmit, receive, idle and sleep mode. When the nodes enters the sleep state and doesn’t sense or cover any target area then there will be an occurrence of blind point and that particular spot where the blind point occurs can be said as an blind spot.