Influence of roof-mounted solar panels - Determination of snow and wind loads acting on buildings with roof-mounted solar panels

Abstract

Roof-mounted solar panels have become common on buildings in Sweden. Normally, loads acting on buildings are regulated in standards and codes, including snow and wind loads. However, no specific guidelines for the obtention of snow and wind loads are available for buildings with roof-mounted solar panels. This has led to divergence and uncertainty among construction companies which considers the influence of solar panels in the calculations of the loads in different ways. Therefore, the aim of this thesis is to establish a general procedure and give recommendations on how to treat wind and snow loads on buildings with roof-mounted solar panels. The project initiated with a study phase in which a literature study was performed. Available standards and guidelines as well as scientific papers and technical reports were studied. Moreover, the study phase included an interview study, where companies with expertise in the field were consulted. The study phase was followed by an analysing phase where different approaches on how to treat the loads were analysed, evaluated and compared. Finally, the thesis’ procedure, results and validity were discussed, and the recommendations were stated in the concluding phase. Different geometrical configurations of buildings and solar panels require different approaches on how to treat snow and wind loads. Through the thesis it was concluded that panels mounted parallel to roofs does not influence the wind pressure on the roof and will not cause snow accumulations due to drifting. However, parallel panels can in some cases increase snow load due to blocking of snow sliding and give rise to increased wind friction. For tilted panels several methods on how to treat snow load were found and evaluated. This resulted in a recommended approach found in the German National Annex to Eurocode 1, DIN EN 1991-1-3/NA:2019. For wind load several approaches based on interpretation of Eurocode 1 were evaluated for tilted panels. The approach concluded to be the most appropriate way to determine wind load on tilted panels was to consider them as canopies. However, it was concluded that, to be able to establish codes for wind load on buildings with roof-mounted solar panels more physical tests and simulations are required. This would make it possible to better evaluate the approaches found in this thesis or to develop new methods. In absence of codes that treat loads on buildings with roof-mounted solar panels, the recommendations resulting from this thesis contributes to a more unified approach to be used among construction companies.