This paper applies exergy analysis and the aqueous sodium chloride solution model (ASCSM) to assess salinity gradient energy potential. For the first time, the effects of two additional salts on the potential besides sodium chloride (NaCl), i.e., magnesium chloride (MgCl2) and magnesium sulphate (MgSO4) - are investigated, leads to achieving more accurate assessments. The rivers flowing into the hyper-saline Urmia Lake in Iran are used as an exemplary case. MATLAB software is applied to analyse data. This research reveals that 9% of the additional potential is associated with MgCl2, and MgSO4.