Impacts of aerosols on available solar energy at Mbour, Senegal

This study aims to evaluate the available solar potential (direct normal on the overall horizontal plane) and to estimate the observed impact of aerosols on solar radiation at Mbour, Senegal (16.958 degrees W; 14. 394 degrees N) using observations from solar instruments and AERONET during 2006. The results show the presence of a good available solar potential. At intra-seasonal timescale, the total and direct normal energy are stronger in May with a mean value of 7 kWh/m(2)/day and February with an average value of 5.50 kWh/m(2)/day. The lower available total and direct normal solar energies are, respectively, found in August (5.31 kWh/m(2)/day) and July (2.90 kWh/m(2)/day). The observations of AERONET show that aerosol optical depth values are higher in June (0.7) and lower in February (0.16). These results are consistent with the observed trends of total and direct normal energy during those months. Case studies of the influence of aerosols on available solar energy show a mean decrease of 10% and 28%, respectively, for the total and direct normal energies. This decrease does not vary much from the rainy season to the dry season, but there is a strong diurnal fluctuation in the rainy season probably due to the presence of cloud droplets. (C) 2012 American Institute of Physics. [doi:10.1063/1.3682078]