Treffer: Sun position and PV panels : a model to determine the best orientation

The correct positioning of photovoltaic panels is essential to ensure the maximum production of electrical energy. Two parameters are involved in this: the tilt angle and the angle of orientation. In the literature, though, the orientation angle receives little attention. In this work, I present an application I developed using the Python programming language in a GIS environment that can help finding the best orientation for photovoltaic panels to make the most from the solar radiation. The developed model required both physical and geographical data. The first type of data was about the solar radiation, and it required information related to the apparent motion of the sun relative to a terrestrial observer and data about the amount of solar energy that hits the ground surface, which was provided by the Swedish Meteorological and Hydrological Institute. The geographical aspect of the project required the creation of a digital surface model from data acquired by LiDAR technology. The GIS environment, where the model has been programmed, was Quantum GIS, which is a Free and Open-Source Software. The application is composed by a main python file and several auxiliary functions that provide interim results. Starting with a list of user-defined information about the area of interest, the application provides a range of both graphical and textual results that help better understanding the features of the solar radiation in the area and therefore provide some useful information for a more efficient use of solar energy. The completed model was tested on a portion of Lund municipality, characterized by a non-built area in the immediate proximity of buildings. The results allowed a better understanding of the annual evolution of shadows, highlighting areas that benefit most from solar radiation and consequently how the shadows affect the average amount of solar energy (kWh/m2)that reaches the ground. The most useful result for the purpose of this study was the identification
Nowadays the interest in renewable energy sources is growing. Solar energy is definitely an endless resource and photovoltaic panels can transform it into electricity. However, correct orientation is essential to ensure the maximum efficiency of these panels. This work aims at developing an application to calculate the best orientation angle of a photovoltaic panel, based on the apparent motion of the sun relative to a fixed point on the Earth. The sun rises and sets at slightly different times every day of the year and consequently describes different trajectories every day. For every given day, time and place, the exact position of the sun is defined by two angles: the angle of elevation and the azimuth. The application is based on a simple physical model that describes the apparent motion of the sun across the sky, and provides its exact location - the two angles - depending on the entered parameters. The area of interest - the point on the Earth where we want to carry out the analysis - is defined by its geographic coordinates and by a digital model of the surface that duplicates the natural and artificial structures on it. As a function of the position of the sun, the structures on the surface will produce different shadows: the change in the pattern of the shadows affects both the amount of energy potentially exploitable by a photovoltaic panel and the definition the optimal orientation of the panel itself. From these physical and geographical backgrounds, the application was developed using the Python programming language. The model developed processes and displays the results in a GIS environment (Quantum GIS). Starting with a list of user-defined information about the area of interest, the application provides a range of both graphical and textual results that helps better understanding the behaviour of the solar radiation and the best orientation angles for photovoltaic panels in the area. The model was tested on a portion of the Lund municipality making t