It appears to be a run of the mill condenser. It probably just exchanges the need to carry water into a battle zone with a need to carry more fuel.
Exactly. But when you have to supply a battle tank with diesel, which would have between one and two thousand horsepower engines, the additional diesel required to produce water is probably not that very significant.
Military logistics is a nightmare. If you can remove one item (water) from the logistic supply chain the benefit would probably far outweight the additional supply of diesel needed.