Wind loads on photovoltaic arrays mounted parallel to sloped roofs on low-rise buildings

The objective of this study was to determine the effects of geometry on the wind loads acting on photovoltaic panel arrays with modules mounted parallel to roof surfaces of low-rise buildings. Specific attention was made to determine the effects of varying the spacing between individual modules, G, and the mounting height above the roof surface, H. The photovoltaic system was modeled as an array of 28 modules on a 1/20 scale building model with a roof slope of 30°. In addition, limited studies were carried out with the array mounted on a flat-roof to assess the impact of roof slope. In general, it was found that larger gaps between modules, G, and smaller gaps between the panels and the roof surface, H, were found to yield lower net wind loads. Minimum loads tend to occur for G/H>~1, for the particular panel size considered in the study. Pressure equalization between the upper and lower surfaces of the modules results in the magnitudes of the net panel pressures typically being lower than those for the bare roof surface. A pressure equalization factor, Ceq, was used as a measure of how much the peak net wind loads on the panels are reduced relative to the peak external loads.

[1]  C.P.W. Geurts,et al.  Wind loads on solar energy roofs , 2007 .

[2]  Aly Mousaad Aly,et al.  Wind-Induced Pressures on Solar Panels Mounted on Residential Homes , 2014 .

[3]  Theodore Stathopoulos,et al.  Proposed new Canadian wind provisions for the design of gable roofs , 2000 .

[4]  Kenny C. S Kwok,et al.  Wind loads on industrial solar panel arrays and supporting roof structure , 2001 .

[5]  Theodore Stathopoulos,et al.  Local and Overall Wind Pressure and Force Coefficients for Solar Panels , 2014 .

[6]  T.C.E. Ho,et al.  The UWO contribution to the NIST aerodynamic database for wind loads on low buildings: Part 1. Archiving format and basic aerodynamic data , 2005 .

[7]  Gregory A. Kopp,et al.  Wind Loads on Low-Profile, Tilted, Solar Arrays Placed on Large, Flat, Low-Rise Building Roofs , 2014 .

[8]  Bogusz Bienkiewicz,et al.  Optimization of Wind Resistance of Photovoltaic Roofing System , 2001 .

[9]  J. D. Holmes,et al.  Wind Loading of Structures , 2001 .

[10]  David Banks,et al.  Use of the Wind Tunnel Test Method for Obtaining Design Wind Loads on Roof-Mounted Solar Arrays , 2013 .

[11]  Maryam Asghari Mooneghi,et al.  Large-scale testing on wind uplift of roof pavers , 2014 .

[12]  B. Bienkiewicz,et al.  Wind loading and resistance of loose-laid roof paver systems , 1997 .

[13]  Jared K Minor,et al.  Experimental Testing of CFRP-Strengthened Reinforced Concrete Slab Elements Loaded by Close-In Blast , 2014 .

[14]  P. A. Blackmore,et al.  Wind loads on stand-off photovoltaic systems on pitched roofs , 2013 .

[15]  Murray J. Morrison,et al.  Aerodynamic mechanisms for wind loads on tilted, roof-mounted, solar arrays , 2012 .

[16]  Bogusz Bienkiewicz,et al.  Wind-tunnel study of wind loading on loose-laid roofing systems , 1992 .

[17]  Andreas Schellenberg,et al.  Wind Design Practice and Recommendations for Solar Arrays on Low-Slope Roofs , 2014 .

[18]  Jon Galsworthy,et al.  Wind loading on tilted roof-top solar arrays: The parapet effect , 2013 .

[19]  Gregory A. Kopp,et al.  Modelling of spatially and temporally-varying cavity pressures in air-permeable, double-layer roof systems , 2014 .

[20]  David Banks,et al.  The role of corner vortices in dictating peak wind loads on tilted flat solar panels mounted on large, flat roofs , 2013 .

[21]  Bogusz Bienkiewicz,et al.  Wind Considerations for Loose-Laid and Photovoltaic Roofing Systems , 2009 .

[22]  K. Suresh Kumar Pressure equalization of rainscreen walls: a critical review , 2000 .

[23]  Yukio Tamura,et al.  Wind tunnel investigation of wind loads on rooftop model modules for green roofing systems , 2013 .

[24]  Julius Lieblein,et al.  Efficient methods of extreme-value methodology , 1974 .

[25]  Gregory A. Kopp,et al.  Velocity measurements around low-profile, tilted, solar arrays mounted on large flat-roofs, for wall normal wind directions , 2013 .