This research considers the production of Potassium Nitrate product, a water-soluble nitrogen–potassium (NK) fertilizer containing 13.7% nitrogen and 46% potassium oxide. Potassium Nitrate (NOP) is produced as a fertilizer grade. The current system incurred high energy consumption, elevated emissions of greenhouse gases, resource degradation, and excessive production costs. Consequently, this research aims to implement the four steps of Cleaner Production (CP) to assess the environmental impacts of Potassium Nitrate products and their main manufacturing processes, and identify the best solution that achieves environmental goals. Environmental assessment was then used to calculate the unit indicators for raw materials, energy, waste generation, product, and packaging. The results showed that the integrated indicator was 5.18, with the energy profile being the most influential factor. Solar thermal and photovoltaic (PV) cell systems were suggested to reduce the high consumption of heavy fuel oil (HFO), including a solar thermal system to support the steam boilers and photovoltaic cells to support the electrical generator. The two alternatives were assessed based on multiple criteria using feasibility analysis and the Analytical Hierarchical Process (AHP). The solar thermal system, comprising 250 evacuated tube collectors, was preferable and resulted in savings of HFO by 121 tons/year, which led to a reduction in gaseous emissions by 375.6 metric tons of CO2 and 21.685 kg of N2O per year. Such improvements can also result in significant cost reductions. In conclusion, applying the CP methodology supported decision-makers in …