Potential cost reduction of seawater desalination

Abstract

The last four years had been witnessing dramatic developments and large cost reduction in the cost of desalinated water produced by large seawater reverse osmosis (SWRO) plants. First in the Eilat 10,000 m3/day plant, followed by the Tampa Bay, Florida project and more recently, by the Larnaca, Cyprus project. The real dramatic decrease relates to the Ashkelon large SWRO plant (in erection phase) where a sensational cost of about “half a US dollar” was reported. The reduced cost has become possible thanks to many factors: improved technology in pretreatment and reverse osmosis membranes, reduced energy consumption, lower interest rates and economics of scale. In this paper the evolution of water cost reduction in SWRO systems in the last decade is analyzed and is used as a basis for projection of further developments and cost reduction. Special attention is given to the new desalinated water standards such as reduced chloride and boron content, imposing an additional cost that can eventually be reduced by using more efficient reverse osmosis membranes and by implementing an improved boron removal technology. Due to these and to other developments a further 20% reduction in desalinated water cost will eventually be realized in the current decade.