PV Wind Loading Analysis

ASCE 7-10 & Wind Loads on PV Trackers

There are three strategies to complying with civil engineering codes to demonstrate safety and longevity of PV arrays (rooftop, ground mount, trackers, etc):

  • Applying Standard Drag & Lift Coefficients Per Geometry
  • Applying Maximum Drag & Lift Wind Coefficients
  • Applying Experimentally Determined Drag & Lift Coefficients from Wind Tunnel Testing

The resulting loads on the panels are resolved by applying the coefficients and applicable safety factors to statistical data for peak gust wind velocity as a function of geographic location as well as to localized features that affect airflow qualities such as boundary layer thickness and turbulence (building corners, hills, proximity to ocean, etc.)

This layered approach provides a conservative way of estimating the maximum loads the structure must withstand during a 50-year mean recurrance interval.

For mechanically coupled systems of panels like what are found on building-integrated photovoltaic systems a clever load-reduction can be demonstrated through wind-tunnel testing that exploits the distributed and transitory nature of the lift and drag forces as they pass over a photovoltaic arrays. By mechanically connecting the panels in the array immediately adjacent panels help keep a panel under gust load stable.