Investigation of Horizontal Solar Radiation Data Source in the World

Photovoltaic (PV) power is the third global power capacity used after hydro and wind. Even though solar energy is abundant and within reach, this energy assessment confronts a big challenge in terms of obtaining measured data due to the limited and unevenly distributed ground-based meteorological stations. To overcome this issue, many studies resort to other sources of radiometric data. Some of the sources are based on satellites. As a result, there is a disagreement of readings compared with ground-based meteorological stations. Therefore, this paper attempts to mitigate the differences by proposing the nearest source compared to measured data. Four different sources (NASA POWER, PVGIS 5, Meteonorm software, and hybrid-based average data) are investigated. The measured data of stations is used as a reference in this study which has been collected from the World Radiation Data Centre (WRDC). The comparative study is made based on monthly average horizontal solar radiation using statistical methods for five continents. Twenty-eight distributed locations are examined. Based on the Global Performance Indicator (GPI), Meteonorm is a suitable data source for Asia and South American continents. In Africa, Europe, and North American continents, the solar radiation source depends on the target location.