Types of Solar Trackers

Types of Solar Tracking Systems

Solar tracking systems can be classified by the mode of their motion. 

There are axes for a moving surface: two horizontal axes and one vertical axis. 

The surface can be rotated around each axis (tilted) to get the right angle for receiving the maximum sunlight. 

When movement or adjustment of the surface happens by rotating around one axis, it is called single-axis tracking. 

On the other hand, when the rotation of the surface happens around two axes simultaneously, it is called dual-axis tracking. 

Application of Single-Axis Tracking System

Single-axis trackers usually move from the east to the west and follow the Sun’s direction. 

Single-axis trackers have only one angle that is used as the axis of rotation. This type of tracker can increase electricity production by more than 30%. 

These trackers provide an efficient, simple, and low-cost way to improve the functioning of solar installations.

Also, these trackers can optimize the performance of the Sun during the summer and spring seasons, when the Sun is in a higher position in the sky. 

The usefulness of single-axis trackers, however, drops as they move farther towards the North. It is because the variance of the solar angle is higher between the summer and winter seasons. 

Also, the performance drops during the other times of the year for the horizontal position of the Sun. At higher latitudes, vertical axis trackers work better. 

This way, solar arrays or panels can track the position of the Sun during winter as well as summer.

Now, let us talk about different types of single-axis trackers such as horizontal, vertical, tilted, and polar aligned.

Application of Dual-Axis Solar Tracking System

Dual-axis trackers have two rotation axis degrees, which are called the “primary axis” and the “secondary axis.” 

The rotational axis can move downwards or upwards to adjust with the angles of the Sun throughout the day.  

Dual-axis tracking allows for the most accurate orientation of the solar device and is said to provide 40% more output through energy absorption. However, these solar trackers are more complex and expensive.  

Dual-axis trackers continually face the Sun as they can move in two different directions. There are two types of altitude-based dual-axis trackers — tip-tilt and azimuth-altitude. 

Typically, dual-axis tracking is used to orient a mirror and redirect sunlight along a fixed axis towards a stationary receiver. 

As these trackers track the sun’s path vertically and horizontally, they help obtain maximum solar energy.

Azimuth-altitude dual-axis trackers can solve both issues. However, these trackers can be expensive and add nearly $3,500–$6,500 to the solar installation cost. 

The function of dual-axis trackers depends on vertical and horizontal pivots, which are controller-guided similar to solar telescopes. These are quite costly, and their usage is generally limited to solar energy systems of commercial grade. 

The accurate tracking of dual-axis solar trackers is also used in a focused solar application, such as mirrors that direct sunlight receivers and convert sunlight into heat.