How does a solar water pump work ？
Solar powered water pumping systems are composed of a power source consisting of one or more solar panels. Solar Panels are made up of photovoltaic (PV) cells. These cells convert solar energy into direct current (DC) electricity throughout the day when the sun shines.
This current then flows to a pump controller which is the brains of the systems. The controller with program called Maximum Power Point Tracking can regulate the speed of the pump motor so it runs at best efficiency. It protects the pump motor from low power and over voltage. It also includes water level sensors or float switches to installed in the well and water tank and switching the pump on and off when water empty in the borehole or tank full. This ensures the pump only pumps water when needed and at the same time displaying the systems status by the LED lights on the controller cover.
Whenever the sun shines the current turns the motor and the pump (surface pumps & submersible pumps) operates and moves amounts of water to storage tanks or irrigation directly. If there is a requirement to run the pump for longer hours e.g. at night, then a battery backup or DC power supply must be included. Battery backup can store electricity during sun shines and to run the pump later when no sunshine, but it does require more solar panels to charge the battery.
And if there's main power, the DC power supply transfer AC electricity to DC, then connected to the controller.
In early systems the motors were driven by DC current through brushes which needed to be replaced frequently. Today’s modern systems use high efficiency brushless motors which are with high efficiency and long lifetime.
Solar water pumping systems will be more and more popular in the near future, most people use pump by solar instead of ac powered pump, it is much more easy for off-grid home water supply, move water from borehole for livestock, the water flow rate can be from 1 gallon per minute to hundreds .