Geographic Aspects of Photovoltaics in Europe: Contribution of the PVGIS Website

The photovoltaic geographic information system (PVGIS) is a web-based knowledge distribution system that provides climate data and tools needed for the performance assessment of photovoltaic (PV) technology in Europe. Geodatabases and simulation models are interlinked with the web interface, thus providing easy-to-use access to users. Interactive maps play an important role in understanding the geographic dependency of the performance of the PV technology. While our previous papers dealt with technical aspects of development and data analysis, here we review lessons learned from the feedback of users. A description of the underlying data and web tools is followed by the analysis of two points that are often discussed when comparing PVGIS with alternative systems: 1) the uncertainty of solar radiation estimates and 2) PV yield predictions. For systems based on the ground observations, such as PVGIS, higher uncertainty of estimates can be expected in mountains, close to the coastline, and in regions with lower density of the meteorological stations. A comparison of PVGIS with other simulation software may show regional differences, which typically reflect: 1) the use of underlying databases that are based on diverse input data (ground-measured or satellite with various observation periods) and that vary in spatial and time resolutions, and 2) the use of different simulation concepts. A cross comparison of the existing systems is needed to identify advantages and limits of their use in solar energy projects.