In an IoT (Internet of Things) system, if image data can be collected in addition to sensor data, the amount of information obtained will increase significantly, which is very useful for monitoring natural disasters, for example. Considering communication speed and covering range, it is assumed that Wi-Fi multi-hop communication is appropriate for image data transmission. Since Wi-Fi consumes a large amount of power, a power supply for sensor nodes is required. Therefore, we are developing a self-sustaining wind power supply called Nishikaze which employs the potential energy conversion method. In this paper, we produced the Nishikaze second prototype. The measurement results of the amount of the generated power show that the Nishikaze second prototype can cover the power required to transmit an image of 500 kbytes at a 10 minute interval assuming that 3 m/s of wind blows for 6 hours in a day, 100 % of the generated power is available, and the active period of sensor nodes is 5 seconds.