Wind loading of rooftop PV panels cover plate: A codification-oriented study

Abstract

The design of rooftop solar panels for wind loads requires provisions to be sufficiently comprehensive to reflect the wind effects on PV module/panel cover plate, individual PV panels, PV panels arrays, and their supporting systems. Unfortunately, the focus of the literature studies and the provisions of the current wind codes and standards is on the net pressure coefficients that can be used in the design of PV panel supporting systems. Particularly, current wind codes and standards of practice do not provide design pressure coefficients for elements on cover plates of rooftop PV panels. In this contribution and along with the intention to examine the characteristics of the wind-induced surface pressures, this paper investigates the surface wind loads of a rooftop solar array of eight panels. The tests were carried out in open-terrain exposure at a geometric test scale of 1:50. In preliminary experiments, additional tests were conducted on two more geometric scales, namely 1:100 and 1:200, to assess the effects of the geometric test scale on the experimental pressure coefficients that would be deemed as design loading for the credibility and integrity of the wind tunnel setup established for codification-oriented studies. The experimental results illustrate that applying the design net pressure coefficients of the current wind codes and standards for the design of PV cover plates will lead to significantly undervalued wind loads. On the other hand, it is found that the external pressure coefficients assigned by ASCE/SEI for gable roofs of low-rise buildings with a slope between 7° and 20° are adaptable for the design of elements on cover plates of rooftop PV panels.