An approach to enhance the efficiency of the solar PV panel in partial shading condition: A Review

Hot spot heating causes permanent destruction of the solar cell structure. Areas with high impurity contaminants and high concentration of transition metals have the most number of hot spot heating. When the operating current of the overall series string approaches the short circuit current of a bad cell then the overall current becomes limited by the bad cell. The good cell becomes forward bias, which reverse biases the bad cell. This leads to large dissipation of power in the bad cell. Enormous power is dissipated in the bad cell or hot spot that results in destructive effects like glass cracking, melting of solder or degradation of a solar cell. The solar panel works best when there is no shade on them. If there is a partial shadow in any one of the arrays, the efficiency of the solar panel drops to a great extent. The shaded cell becomes reverse biased so maximum power will be dissipated on the shaded cell. The heat developed due to the reverse biased of the shaded region adds to the dissipated power