AWWA JAW64843

As freshwater sources become increasingly stressed, many coastal communities are looking to seawater desalination to augment their supplies and meet growing demand. Seawater desalination is an energy-intensive process, however, with energy expenses accounting for a significant part of the process operating cost. This article looks at the factors affecting energy consumption for seawater desalination and discusses design and technological developments that can improve efficiency. Although the salinity of the feedwater affects the energy consumed during desalination, energy consumption is also influenced by such factors as recovery, flux, membrane type, ancillary processes, type of equipment, and energy-recovery devices. To improve efficiency, utilities must take into account design and operation of all these components. Recent advances in desalination technology are making the process more energy-efficient and cost-effective. Water providers can do their part by optimizing system design to foster energy efficiency so that, ultimately, more communities can economically tap into untapped sources of supply. Includes 19 references, table, figures.