Optimum design of PV-RO system solar-powered sea water desalination without storage in Saudi Arabia (Case study)

Abstract

Bad effects associated with drinking water are a serious problem in regions with low freshwater supplies and high frequency of droughts, just like Saudi Arabia. Desalination of water is an excellent solution to this issue, but this process uses a great deal of energy, which mainly comes from fossil fuels. Power provided by photovoltaic cells for desalination provides a cleaner and cost-effective substitute. The focus of this survey is to find means to run reverse osmosis desalination plants by the electricity generated by solar cells without storage to find the cost per unit electricity (kWh), and to estimate the highest energy percentage, which can be generated by solar panels in the day time. That is the reason why a reverse osmosis plant was selected for the case study. The data for solar power produced and consumed for desalination of brackish water into potable water is based on actual measurements acquired from the direct observation of a reverse osmosis desalination facility located in Saudi Arabia. It was observed that during summer months, a larger amount of solar energy are produced compared to the winter months because of greater daylight hours in summer. It was found that the maximum electrical power generated at midday by the photovoltaic solar plant lies within the range of 9.15 MWh to 17.95 MWh. By studying the results of the chosen plant as a case study, it was found that the percentage of non-usable energy is less than 2% in a plant whose size is 20 MW. In this case, 20 percent of total consumed energy could be provided at a price of around 0.025 €/kwh. The expenses for power produced exceeds 0.043 €/kwh when the plant is greater than 60 MWp.