Potential for economic solar desalination in the Middle East

Fresh water forms only about 1% of the total water available on earth. Technologies for the desalination of seawater have considerably matured in the last decade. However, the energy required for the desalination is usually expensive in arid areas where fresh water is required. Renewable energy provides a clean, free, and low-maintenance source of energy for desalination, limited only by their initial cost, and the variability of the available energy. In this paper the potential use of solar energy for the desalination of seawater in the Middle East is evaluated. Multi-Stage Flash (MSF) desalination requires large amounts of energy, while Reverse Osmosis (RO) desalination is more energy efficient. Solar distillation is a very simple and direct method that may be used, requiring only large flat areas of land, having no running energy costs and being very suitable for remote areas. Photovoltaics is another promising renewable energy source for seawater desalination in the Middle East. It is best suited for the RO and Electrodialysis (ED) methods. The desalination plant doesn't need to run continuously, and therefore no storage batteries are required. Diesel and / or natural gas may be used as a backup energy.