Analysis of solar exposure potential of different roof types with consideration of overshadowing, on the example of selected buildings located in the city of Nowy Sącz

Abstract

The subject of the research was to determine the solar exposure potential of selected roofs in order to check their suitability for installation of solar panels. The research area covered selected objects from two districts in Nowy Sącz: Biegonice and Dąbrówka. The analysis was conducted both, for an industrial building - the hall of the CARBON SA Plant and residential and farm buildings typical for the rural region. A total number of 14 roofs of rural buildings and 10 roofs of industrial buildings were considered during the analysis. The research was carried out for different kinds of roofs – pitched, gable, multi-pitched and flat. They were vectorised and converted into three-dimensional polygons on the basis of the point cloud resulting from aerial laser scanning.
Vector models of roofs were prepared in a CAD type application, where the point clouds were also pre-filtered and then roofs were vectorized in the three-dimensional space. In the case of an industrial facility, neighbouring buildings were also inspected which might overshadow the plant roofs. Solar Calculator [Solar Exposure Calculator] was used to calculate solar radiation, which allows to estimate solar exposure and insolation for a particular roof. Diel calculations were made for four characteristic days of the year - the longest and the shortest day and two equinox days.
The results were presented in the form of illustrations and tables. The analysis allowed to identify and calibrate roof slopes in terms of the calculated values of insolation and to determine the overshadowing effect generated by neighbouring objects. At the end of the paper, conclusions from the analysis were presented and the benefits of this type of calculation were pointed out.

Received 31.12.2017 Accepted 31.01.2018 Published 15.05.2018