A major concern in sensor networks is to reduce the data traffic and the energy consumption to extend the lifetime of the network. In this regard, radio transmission is the dominant factor in energy consumption. Therefore, the routing policy has a significant impact on the overall lifespan of the sensor network. For instance, pure multi-hop routing, e.g., tree-based routing, has the drawback that nodes closest to the data collection point (sink node) consume their energy and die first. In this paper, we propose an opportunistic routing mechanism that aims to extend network lifespan by balancing energy consumption. Our approach distributes the power consumption in the network by altering the communication range when applicable. Our experiment results suggest significant improvements when compared to tree-based routing pure multihoping and LEACH based routing.