Solar technology is very well suited to pumping water, even more so than the traditional windmill. A typical system includes one or more solar panels, an efficient 12 volt DC pump, a controller (with float switches), and a "linear current booster"
As long as it's daytime and the float switches show that the water source is not empty and the cistern in the house is not overflowing, the pump will run. The linear current booster allows the pump to run even if it's cloudy out.
Linear Current Booster (LCB)--This device trades voltage for extra current to start a pump. Electric pumps take more power to start up than they take to run, and the LCB takes care of this problem. It will allow your pump to start and run even on cloudy days.
Vijay Gupta
Engineers India Research Institute