Solar trackers adapted to desert conditions: what needs measuring

Soltec is a leader in the manufacture and supply of solar trackers for utility-scale PV plants. Since it was founded in 2004, Soltec has developed and implemented different solar trackers with the aim of achieving optimal performance in any solar plant, making it possible to install them in any location.

Since 2014, Soltec has been supplying and installing several projects in desert environments, including Chile’s Atacama Desert. Projects in this type of extreme locations have been the test bench for some of the standard features of Soltec’s trackers and profitable innovation. To provide customers with the best service, several challenges have to be addressed, including:

  • Higher tracker efficiency density.
  • Better use of the ground for tracker installation.
  • Tracker stability on hard, rocky or clay surfaces.
  • Intermittent flooding, tornado-force winds and high temperatures.
  • Profitable installation and operation.
  • Data communication over long distances.
  • Logistics and installation practices in remote, hostile environments and at high altitudes.

For this type of projects, Soltec has had to address the extreme challenges of desert locations, high altitude areas with extreme wind events, remote and extremely isolated sites, far away from towns and infrastructures, etc., all of which results in complex supply logistics and installation situations that put the project time line at risk.

Despite these challenges, the Soltec trackers and the company’s engineering and logistics teams have always been able to adapt to any terrain, and to any circumstance. The trackers have had to be adapted to rocky ground, tornado-force winds and intermittent flooding. The StringRunner has been incorporated into several projects as a solution for installations on slopes with the best site orientation, where other solutions could not have been constructed without unfeasible civil works. The StringRunner manages and protects the PV cabling inside the torque tube, avoiding shading by the cables and generating greater gain.

In addition, steep slopes can be used, thereby making use of the entire project area. The Soltec trackers are able to adapt to slopes of between 11% and 14%, with the tracker mechanism showing high levels of efficiency on this type of ground.

The ‘La Silla’ solar plant project incorporates the first bifacial tracker specifically designed for mounting bifacial panels in utility-scale solar plants. In 2015, Enel Green Power presented Soltec with the challenge of optimising the efficiency of the emerging bifacial PV technology at commercial level. This PV plant is also located in a remote highland area of Chile’s Atacama Desert and powers an astronomical observatory. Every plant element is integrated into the SCADA system: inverter, tracker, video surveillance, weather station, pyranometer, etc., to handle any adverse situation.

To develop its trackers, Soltec undertook different tests to try out the static wind load coefficients obtained in different situations. For extreme wind situations – very common in desert environments – speed pressure tests are used inside a wind tunnel as well as Dynamic Amplification Factors (DAF). These tests are able to measure the resistance of the trackers and understand the structural reinforcements required by the solar tracker depending on its specific position. In this way, Soltec guarantees that its trackers are always adapted to the project, achieving optimum levels of efficiency and an enhanced return on investment for customers.