Seawater Desalination
Seawater desalination produces fresh water from the ocean, principally by reverse osmosis (membrane) or thermal distillation (MSF/MED). Global installed capacity exceeds 100 million m³/day, concentrated in the Middle East but growing fastest in Asia and North Africa.
Technology mix
Thermal processes — multi-stage flash (MSF) and multi-effect distillation (MED) — historically dominated the Gulf, exploiting cheap cogenerated heat. Reverse osmosis, more energy-efficient and modular, now accounts for the large majority of new contracted capacity worldwide, including in the Gulf itself as renewable power reshapes plant economics.
Environmental considerations
Key impacts are energy use and associated carbon (mitigated by renewables and energy recovery), intake effects on marine life (addressed with subsurface intakes and low-velocity screens), and brine discharge, which requires diffuser design and monitoring to manage salinity and any additives in the receiving environment.
- [1]Desalination: A National Perspective. US National Research Council, 2008.
- [2]IDA Water Security Handbook. International Desalination Association, 2023.