Influence of typical meteorological years on the optimization of incident solar radiation for PV applications in Portugal

Abstract

In Portugal, the values used for forecasting the production of solar thermal systems, photovoltaic and thermal simulation of buildings are periodically updated due to climate changes. There is a special interest in optimizing these systems since Portugal has high insolation levels and the sector has benefited from technological developments that improved its efficiency and costs. The main objective is the analysis of typical meteorological years influence on the optimization of incident solar radiation, applied to the municipality of Braga (north of Portugal). A study was carried out on the fundamental concepts related to solar geometry, and the best methods for data processing were identified to develop an analysis tool, in MS Excel, to compare the selected climatic databases. Different solar tracking configurations were also considered: biaxial, polar axis, horizontal axis and fixed tracking systems. The analysis shows that the climatic database update resulted in the increase of total incident solar radiation when comparing both typical meteorological years. The polar axis present values very close to the orthogonal incidence biaxial system, which maximizes the incident solar radiation in the panel. The application of simple atmospheric models to estimate/predict the total radiation incidence presents more conservative values when compared to the more complex models.