What are the different kinds of trackers?
There are two main types of trackers: Active and Passive.
Active trackers use motors, irradiance sensors, timers or other programs to follow on the suns path on either a single axis or dual axis.
Passive trackers use the weight of a gaseous refrigerant in a sealed frame to track the sun. They tend to react slower in colder climates and can only be a single axis.
Tilt & Roll Tracker