In wireless sensor networks, the necessity of reprogramming becomes more and more important due to the inaccessibility of the sensor nodes. Because reprogramming produces a large amount of data, it consumes a great deal of energy and causes frequent collisions. Many conventional studies regarding reprogramming attempt to reduce the energy consumption and collisions. However, they overlook transmission power control which is highly related to energy efficiency and the collision problem. In this paper, we present a novel reprogramming scheme that uses dynamic transmission power control. The protocol deals not only with the energy consumption of each sensor node but also the network load distribution. We prove that our protocol extends the lifetime of the sensor network through OMNeT++ simulation results.