Sunlight is the fuel of solar panels. So, more exposure of the solar panels to sunlight means higher energy yield, more efficiency and more water output of the pumping system.
Tracking is a means of achieving the maximum possible exposure. It is a mechanism for moving the solar panels as the sun moves across the sky.
Tracking mechanisms can be manual or automatic. Though the automatic trackers give much more output, they are very costly. So, manual tracking is usually preferred in India.
Tracking can be done daily as well as seasonally. Since the position of the sun changes considerably in winter and summer, seasonal tracking can increase the output by as much as 20%. The tracking mechanism has in-built adjustments suitable for a particular location.
The operational instructions are as follows:
Daily sun-tracking: It is an important part of the operation for maximising water output. It is provided to follow the path of the sun throughout the day from sunrise to sunset from east to west. The support structure has provision for tracking in 3 positions:
Morning: At sunrise the solar panels should be facing east.
Mid-day: At noon the panels should be horizontal.
Afternoon: During the afternoon the panels should be facing west.
Seasonal tracking: It is provided to adjust to the seasonal variations in the path of the sun from north to south. In India, the solar pv panels should be facing south. The tilt angle towards the south depends upon the latitude. Seasonal adjustment is done twice a year, for summer (April) and for winter (October).
South facing tilt angle should be adjusted as follows:
Summer position: latitude -15°.
Winter position: latitude +15°.
For example, Punjab is at 30° latitude. So, the tilt angle will be 15°during summer months and 45°during winter months.
In case of strong thunderstorm or dust storm change the angle to 0 degrees. The array should be moved slowly, when changing its position. If it is not possible to tilt the panels every day, they should be fixed in the middle position.