In this paper, we present a new data dissemination protocol that conserves battery power by reducing the amount of communication required to disseminate sensing data from sources to mobile sinks. The proposed scheme, called ondemand data dissemination (ODDD), focuses on the elimination of resource waste in large-scale dense sensor networks caused by virtual grid construction and maintenance. The virtual grid-based approaches in the literature build grids over the entire network including the areas where a data collector never roams into. However, in the proposed scheme, a source constructs a dissemination line along the X-axis only. To evaluate the effectiveness of the proposed scheme, we have conducted a comprehensive simulation study using the ns2 simulator. Our simulation results show that ODDD outperforms other existing schemes in terms of packet delivery ratio and delay. ODDD also achieves significant energy savings by reducing the overhead caused by grid constructions and frequent local flooding.