Urban-Scale Rooftop Photovoltaic Potential Estimation Using Open-Source Software and Public GIS Datasets †

Abstract

Highlights: This study highlights the needs and means of estimating open-source photovoltaic power output in future urban areas. The proposed methodology includes the building shadow analysis as the first of the key inputs. The second key input is the statistical analysis based on the PVGIS tool, which consists of 16-year data processing and the evaluation of the photovoltaic installation aspect, slope, and, therefore, general efficiency of such systems in the specified sample area in Bratislava, Slovakia. The results from the proposed methodology are presented, and future research in open science in this area is discussed. What are the main findings? The photovoltaic power estimation in predominantly urban areas without building shadow analysis is not a good approximation, especially in winter, when the building shadows cover the largest areas. This aspect is often neglected in studies with very large sample areas. Many current methodologies for photovoltaic power output estimation are of a proprietary nature, resulting in limited use in academic, public, or other non-commercial use. What is the implication of the main finding? Urban areas need to be examined with proper tools and algorithms, with the most precise knowledge of meteorological, geospatial, and geographical data. There is a strong need for a completely open-source methodology for various aspects of urban planning, including smart city concepts, energy efficiency, and low-carbon footprint engineering in general. This paper aims to effectively estimate urban-scale rooftop photovoltaic potential using strictly open-source software and publicly available GIS data. This approach is often neglected; however, its importance is significant regarding technology transfer and general commercial or academic ease of use. A complete methodology is introduced, including the building shadow analysis. Although many papers are published in similar areas, very few reveal the specific steps and functions in the software used, or the computational core of some part of the estimation is a “black box” of a commercial service. Detailed irradiation parameters can be obtained using the proposed methodologies, and the maximum photovoltaic (PV) power output in the area can be estimated. The great advantage of this model is its scalability and the easy way of modifying every computational parameter. The results and limitations of the proposed methodology are discussed, and further development is suggested. The presented model is based on a sample location in Bratislava, Slovakia, with an area of circa 2.5 km2.