A solar pump uses power derived from sunlight that is converted 

into electrical power by Solar Photo Voltaic (SPV) modules, which

give higher power output in the afternoons and lower power output

in the early morning and evening. As a result, solar pump works on

varying power input and gives varying water output at a given pump

duty head. The most important parameters to select a give pump

are: how much water is needed daily ,at what pump duty head, and 

at which location .The location is important because solar energy

varies from region to region, and sizing of solar panels depends on 

the capacity of solar pumps and also solar radiation of that region.