When related to the solar panel, the fan can run; and might be used on my own by means of means of plugging into the computer's USB port. When related to a photo voltaic panel, the fashion the fan works will depend on the sunlight. When the photo voltaic is irradiated to generate hot air, the fan instantly rotates to deplete warm temperature in time, ventilate, save the hassle of pulling wires, and it is and additional convenient. There is no rechargeable battery in the fan; while you would really like the fan to work at night, you need to use the power pack. Specification: Solar panel chip: Polysilicon Solar panel power: 5W, 6V Panel size: 14/5 Mini fan: Size: four inches Power supply: USB plug, 5V USB cable length: 70cm/27 Material: Metal colour: black Package Contents: 1 x Solar Panel 1 x Fan Only the above kit content, other merchandise aren't included. Note: Light and assorted exhibits can cause the colour of the object within the photo somewhat diversified from the real thing. The size allowed error is +/- 1-3cm.