I think improved efficiency is more about improving membrane...

I think improved efficiency is more about improving membrane technology than it is about how the saltwater is forced through the membrane.

http://cleantechnica.com/2015/04/03...-efficient-graphene-desalination-membrane-99/

I remember reading that Kwinana Desalination Plant had to cease freshwater production twice in one year due to high levels of salt in Cockburn Sound. Probably a reason why WaterCorp has signed a memorandum of understanding with CWE who will be discharging concentrated brine in open ocean.

I am of the opinion that desalination can be decentralised more easily by having numerous smaller CETO plants spaced out along the coast rather than just a few mega plants.

MAK Water and CWE have joined forces for the desalination side of PWEP. They also have an agreement in place for Chile. MAK Water specialises in containerised desalination plants that can be scaled up or down depending on the need. Decentralised desalination would help to reduce environmental damage through excess concentrations of salt.