Development and evaluation of solar powered sprayer with multi-purpose applications

This invention is about an agricultural pesticide sprayer, which uses solar energy as source of power for spraying. It consists of a solar panel of 20 W capacity, a 12V DC battery, charged by solar energy received by the solar panel, a DC motor, operated by the battery, a pump, to spray the pesticide and a tank to hold the pesticide (in the form of solution / liquid). The entire unit is portable and is operated by one labour. The discharge rate of the sprayer during laboratory and field conditions were measured, the average discharge rate during both laboratory test and field test were more or less same which was about 0.023 l/s (82.8 l/h). The performance evaluation of the sprayer was carried out for spraying in different crops viz., cotton, green gram, onion etc in farmer's fields. The walking speed of the operator is about 2.8 km/h and swath width of the sprayer is about 0.6 m, which corresponds to a theoretical field capacity of about 0.17 hectare per hour. The effective field capacity of the sprayer was observed to be 0.14 ha/h which corresponds to an average coverage of 1 ha/day of 8 hours operation. As the equipment does not use any other external source of power and that it is operated by the user himself, it reduces drudgery, is quite economical and eco-friendly as it uses solar energy which can be easily affordable by small and marginal farmers. Further, its power can also be used for multi-purpose applications such as charging the battery of mobile, operating the radio and lighting the domestic light etc., which makes it more economically viable technology.