The enthalpiesEnthalpy related to the dissolution of smelterSmelter-grade primary and secondary aluminaAlumina in aluminium cellsAluminium cell were calculated. The following was considered: (i) the heat content of aluminaAlumina containing fluoridesFluoride and other impuritiesImpurities, (ii) the heat of dissolution, (iii) enthalpiesEnthalpy for bath evaporation and hydrolysis, (iv) enthalpiesEnthalpy for desorption of H2O, HF, and SO2, (v) enthalpiesEnthalpy for melting of solid fluoridesFluoride, vi) enthalpiesEnthalpy for fluorination of Na2O and CaO, and (vii) aluminaAlumina production from fluorination of Na2O and CaO and hydrolysis of bath. A typical secondary aluminaAlumina showed 0.022 kWh/kg Al higher energy consumptionEnergy consumption than the corresponding primary aluminaAlumina, and 0.055 kWh/kg Al higher energy consumptionEnergy consumption than a hypothetical dry aluminaAlumina without impuritiesImpurities. It is recommended that the enthalpyEnthalpy terms are considered by detailed calculation, or simply by adding a fixed term to the cell reaction.