Characteristics of various radiative fluxes: global, tilted, direct, and diffused radiation—a case study of Nigeria

A proper understanding of what the earth’s surface receives when sun rays leave the sun’s disk is important as this informs the decisions made by meteorologist and the likes in utilizing solar energy. In this pursuit, this study was performed by taking stations from each geological region in Nigeria. Data were obtained for the Global Horizontal Irradiation (GHI), Global Tilted Irradiation (GTI), Direct Normal Irradiation (DNI), and Diffused Ratio ( K d ) for 12 years (2005–2016). The Diffused Horizontal Irradiation (DHI) was calculated and the results were presented. It was concluded that the latitude, local weather conditions, elevation, etc. were major factors that contributed to the amount of solar energy that can be received in a particular location. Results showed that for the locations in the northern region of Nigeria where the local weather conditions are less humid (characterized by clear skies), lower diffused irradiation (DHI) and higher direct irradiation (DNI) were observed; the reverse is the case for the locations around the south of Nigeria. This shows that global solar irradiation or GHI would be received more in the northern locations than in the south, leading to the importance of understanding the GTI which involves tilting the Solar PVs or receptors to angles that would receive more DNI than DHI. These angles were displayed and we concluded that solar trackers may not be necessary when users understand the presented results. Results can be adopted for other locations with the same latitudes around the globe.