1. Energy Research Laboratory, Renewable Energy Section (LRE/SENC), Institute for Geological and Mining Research (IRGM), Nlongkak Yaounde, Cameroon
2. Université Clermont Auvergne, CNRS, Clermont Auvergne INP, Institut Pascal, Clermont-Ferrand, France
3. Department of the Renewable Energies, the National Advanced School of Engineering of Maroua, University of Maroua, Maroua, Cameroon
4. National Advanced School of Mines and Petroleum Industries, University of Maroua, Maroua, Cameroon