Prospects for Desalination as a Water Supply Method

In this paper, four major parameters of fresh water production from saline sources are discussed. The parameters are desalination technology type, water sources input type, energy sources and productions cost per cubic meter. Five different types of desalination technology are presented and bench-marked for long-term use. RO and MSF are dominant technologies. Six different input water sources are used. There is no significant change in the sources distribution during the past 20 years. Wastewater seems to be more important, but in 2009 only 5% of all raw waters. Three different energy supplies are reviewed: conventional fossil based energy, nuclear energy and renewable energy sources. At present, the cost of desalination using a conventional source of energy is lowest. Statistical analysis points indicates a total production cost of less than US 0.5 $/m3 in 2020. This will probably continue to drop due to effects of scale and reach US 0.35 $/m3 after year 2020. Wastewater is less costly to desalinate, approximately US 0.3 $/m3 from the year 2015. Brackish water will reach US 0.2 $/m3 at year 2015. The paper takes China as an example, presenting the desalination status of China from the four aspects.