During daytime whenever sufficient sunlight is available the DC Current produced by the Solar panel directly powers the Air Cooler. In cases of low Sunshine & during the night times a battery backup is required to run the Cooler. It is a very highly efficient cooler that uses water to perform the cooling function. The advantage of using such a type of cooler is that it is economical because it totally eliminates the consumption of AC power. During summer you will never have high electricity bills by using this cooler.