NEXTracker is an innovative ground-mounted, single-axis tracker solar energy product that relies on a mechanically balanced design to reduce the power needed to rotate each row of modules as they track the sun. Each row is able to move independently of the others, eliminating the need for drive shafts that normally connect several adjacent rows to a common motor. Furthermore, NEXTracker’s architecture gives it a 120° tracking range, improving its ability to produce power throughout the day.
In 2012, Solaria (which spun off NEXTracker as an independent company in 2014) hired CPP to measure wind loads for this first-of-its-kind design. In addition to testing various tilt angles, our engineers were also tasked with evaluating a stow configuration that would protect the trackers from damage at night and during high-wind events.
Our designers created a 1:30 scale model of a representative field of NEXTracker rows, featuring nearly 1,000 pressure taps to measure wind pressures at key locations along each row. Then our technicians put the model through its paces in the wind tunnel, measuring pressures at every tap for a variety of module inclinations and all wind approach directions.
In a study like this, data collection is the easy part. But making sense of the large data sets that result takes experience, intuition, and a nuanced understanding of the wind patterns that develop in and around fields of solar collectors. Using specialized software that our solar team developed just for these kinds of studies, we put together the individual pieces to create a comprehensive picture of how the NEXTracker system would behave under a wide range of configurations and wind conditions.
We also used the wind tunnel data to predict how vibration would affect loads along the rotational axes and offered recommendations on how to account for these dynamic effects. The solar industry is increasingly recognizing that specialized approaches like wind tunnel testing are needed for dynamic wind loading because building codes simply don’t apply to these kinds of thin, flexible structures.
The recommendations we made to Solaria enabled their designers and engineers to make modifications where needed and ensure the success of the NEXTracker system. CPP’s leadership in understanding the effects of wind on solar collectors ensured that the developers of NEXTracker had the critical information they needed to design a safe and efficient system.