Façade photovoltaic systems on multifamily buildings: An urban scale evaluation analysis using geographical information systems

In this paper is presented the application of a comprehensive methodology for the prediction of the photovoltaic (PV) potential in building façade surfaces and particularly with an application example for the Greek residential sector. The methodology is based on the determination of typical façade PV installations for Greek multifamily buildings considering architectural and technical aspects. The proposed solutions are then evaluated with dynamic energy simulation to determine the most efficient ones. The results produced in this way are used as baselines for a large scale analysis, which is implemented in the urban area of Greece׳s second largest city, Thessaloniki, by means of Geographical Information Systems. This led to the exploitable PV potential and the solar electricity production as well as the respective CO2 savings. One of the interesting findings is the discrepancy between the architectural availability and the overall solar suitability of façade surfaces. This discrepancy is based on the following main factors: firstly, the high density of the built environment consisting of street canyons with high Height-Width ratio, secondly the varying orientation of the buildings and, finally, the buildings׳ typology, with the complex geometry due to verandas, erkers and semi-enclosed spaces.