What is a solar tracker and why can it increase the overall performance of solar power plants?
When building a solar power plant on a greenfield site, we must carefully consider the location and angle of the solar panels in relation to the sun. The optimal angle and orientation have a significant impact on the total energy yield per day/year. To maximize performance, a device can be added that tilts the solar panels toward the sun. Such a device is called a solar tracker.
A solar tracker is a device that, based on the position of the sun, can optimally tilt solar panels so that their performance is as high as possible at any given moment. There are two types of solar trackers for tilting panels: single-axis and dual-axis.
The panels are tilted using electric motors, which move the entire metal structure and thus also the panels attached to it. The movement of the panels is controlled by a program that precisely determines the position of the panels in relation to the sun.
Types of solar trackers
Solar trackers can be divided into two basic groups according to the method of tilting: single-axis and dual-axis. This means whether the panels tilt in only one direction or whether they tilt completely according to the movement of the sun.
Single-axis tracker
Tilting occurs in only one axis, so we cannot accurately track the movement of the sun and eliminate lower panel performance, for example in winter. With this type of tilting, the panel tilt control can be set fixed according to time with possible correction for the season. For this type of tilting, east-west placement is suitable for better performance during periods when there is typically higher demand for electricity.
This tracker may be suitable as an addition to an already functioning solar power plant, which usually has panels tilted towards the south.
Dual-axis tracker
With a dual-axis tracker, the structure with panels moves in two axes, allowing us to precisely track the sun’s movement across the sky. This means we can maximize the solar power plant’s output throughout the day. In this case, control is more complex, and each individual structure with electric motors and panels can track the sun independently.
Výkon se solárním trackerem
When using a solar tracker, we can achieve up to 20% higher total energy yield. They can be a suitable addition to existing solar power plants or as a stand-alone structure in an urban environment. By tilting the panels, we can achieve higher performance, especially in the morning and afternoon hours, when south-facing panels do not perform as well. This can be clearly seen in the graph above, where panels with trackers have higher performance in the morning and evening.
It is always necessary to carefully calculate the return on investment, as the cost of solar trackers can be higher than the installation of solar panels alone. Nowadays, static panels are more commonly used in multiple directions, as this is usually a cheaper solution.
When is it appropriate to use solar trackers?
Solar trackers can be an interesting alternative in built-up areas or as architectural elements in cities and towns, providing natural shade and thus cooling cities and generating energy. One such example is Smartflower, a solar tracker that is not only a design feature suitable for cities, but also a good example of how solar panels do not always have to be unsightly rectangles.
A disadvantage of dual-axis trackers can be the susceptibility of the entire structure to stability issues. In high winds, this can place a heavy load on individual parts, which must be taken into account.
Smartflower dual-axis solar tracker:
Smartflower dvouosý solární tracker:
Source:
https://www.researchgate.net/figure/Fixed-and-Tracking-solar-power-energy_fig7_238735284
https://solarity.eu/cs/blog/poskytovatel-solarnich-trackeru-sat-control/
