This is a component -- what's the device model? The energy cost of crossing that gradient will continually increase (you could use gravity, but you still have to clean the briny side).

The of course brine disposal is a problem.

Don't get me wrong -- I love this work -- but it's just part of the solution.

For a lot of people in poor, hot regions a simple evaporator of concrete with a glass top is surprisingly effective, both cap ex and op ex (both pretty low, though they assume a tiny cost of labor).