closed loop system

I cant find the right thread but at one stage we started talking about how the water would be filtered prior to entering the system.

I thought of it when i came across this line in an interview with Tim Sawyer, CNM's Oceanographer by the looks of things:

"TIM SAWYER : That's right, the same sea water is put straight back out to sea, nothing is added to it, nothing is taken away. In fact we're also working on a closed loop system as well."

http://www.abc.net.au/ra/innovations/stories/s2408911.htm

It's only one line but a very interesting one - it suggests that CNM are looking at the possibility of a closed loop system - i imagine that is where no (or very little) new water is added to the system, it just flows around in a loop, continually being pressurised as it passes through the CETO units. It makes sense, the water is coming ashore, then going back out to sea - why not keep it in the system (if it doesn't reduce efficiency too much). There's no indication that they will proceed that way, but it's a really interesting thought. Not one that i had considered.

(i found that snippet while i was looking for info on Garden Island, wondering if the increase in Defence spending that's just been announced might make the federal govt keen to, in effect, give money to itself by giving a renewable energy grant to CNM to produce electricity for the Navy base - any ideas?).