Found this. http://www.desware.net/Energy-Requirements-Desalination-Processes.aspx http://www.desware.net/Energy-Requirements-Desalination-Proc... Seems like

Found this. http://www.desware.net/Energy-Requirements-Desalination-Processes.aspx http://www.desware.net/Energy-Requirements-Desalination-Proc... Seems like reverse osmosis takes 3.5-5.5 kwh/m3. Vs 0.86 theoretical. So 15 to 25% of theoretical efficiency.