Analysis of Potential Distribution and Size of Photovoltaic Systems on Rural Rooftops

The present study as part of the joint research project “Smart-Power-Flow”1 (at Reiner Lemoine Institute for Renewable Energies) focuses on modelling PV systems´ distribution in German rural communities. Although solar power energy systems in Germany have been increasing exponentially for the last 20 years (WRITH 2014), the majority of literature on PV potential has focused on rooftop PV systems in urban regions, and a small number of publications consider the typology of small rural communities. These areas, although less populated than cities, are where the highest PV potential in Germany is expected (DENA 2010), and, at the same time, where the availability of laser scanning data is highly incomplete, or not affordable for small administrations or projects. Several authors have used remotely-sensed imagery to quantify the PV potential on a regional scale, but only few authors (KJELLSSON 2000, BERGAMASCO & ASINARI 2011, JO & OTANICAR 2011) have attempted to use high-resolution images to quantify the suitable rooftop surface on a building basis, and none of them have addressed the particularities of rural communities. The aim of this study is to create a methodology, which predicts the size and location of future photovoltaic systems on rooftops, based on generally accessible data, and that is easily reproducible on a building scale for other rural villages. The methodology’s input data comprises high-resolution aerial imagery, GIS building footprints from the Landregister map, and the Bavarian database of photovoltaic systems. In addition, the method is tested using two types of images: a) official orthophotos from the Bavarian Land-survey Office, and b) Google Earth™ orthophotos, to assess the accuracy of freely available data to the project. The results are compared in the discussion section.