Practical design of a small-scale PVRO desalination unit using longtime measured water quality reports: A case study for Khuzestan, Iran

Abstract

This study aims to present a practical design of a small-scale photovoltaic-powered reverse osmosis desalination unit (PVRO) based on a local river’s 9-year measured water analysis reports for Buzi-ye Seyf village. After preprocessing the dataset, we used WAVE software to design the RO system, considering nine scenarios containing the most extreme possible situations regarding feed water total dissolved solids (TDS) and temperature. Next, considering negligible desalination electricity tariffs in Iran, the photovoltaic system was designed using PVSOL software with two targets: CO2 reduction and peak shaving in daytime peak hours during spring and summer. During these seasons' 184-day period, the PV system managed to meet the energy demand for 154 days, exporting 2332.86 kWh to the grid and importing only 136.8 kWh from the grid on days when energy fell short. It was found that in the feed water TDS of 3035 mg/L, every 10 degree elevation in the feed water temperature results in an 83.33 Wh/m3 reduction in the SEC and a 70.49 mg/L rise in the permeate water TDS. Analyzing the scenarios demonstrated that the influence of increasing TDS had a more significant effect on SEC compared to the reduction in temperature. In addition, the PV system was shown to successfully achieve the task of peak-shaving for the investigated period while preventing 15467 kg of CO2 emissions per year. Thus, the designed system provided a practical way of solving the drinkable water issue in Buzi-ye Seyf and areas with similar conditions.