Types of Solar Trackers
Passive Trackers (Thermally operated). These trackers are inexpensive and quite reliable for they require no electrical parts. These are thermally operated and use a low boiling point working fluid (Freon 12). The fluid is driven to one side by solar heat vaporizing the fluid, driving the hydraulic dampers which are used to control the movement of these trackers. Passive trackers work best in places where sunlight is abundant. They perform less well in cold and windy places. The drawbacks include the requirement of solar heat making it ineffective during winter months. Also, it takes an hour in the morning to heat the system enough to operate. Another disadvantage is that it only tracks the sun’s east to west axes and does not track the seasonal north to south motion of the sun. This results to manual adjustments at least four times annually to compensate for the seasonal differences.
Active Trackers (Electrically operated). These are mechanized devices that require routine maintenance. Active trackers use motors and gear trains to lead the tracker as directed by a controller responding to the solar direction. They are extremely precise in measuring the sun. The dual axis trackers track the sun’s movement from east to west and the seasonal changes along the south to north axis. The photovoltaic (PV) array is always perpendicular to the direction of the sun. These trackers do not rely on temperatures so it can efficiently operate even on winter months. The only concern about active trackers is the regular maintenance required to run them.
Solar trackers are one great way in making the best out of the solar panels. Choose the solar tracker that will work best in your area of location. Passive or thermally operated trackers will be most efficient if you live in a place with temperate and have a lot of sun. On the other hand, active or electronically operated trackers would be the best system that can be used in colder climates and cold winters.
Whichever system is chosen and use, it may be practical and beneficial to have one on any PV system when affordable.
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