Desalination is incredibly expensive. At this point, they aren't completely out of water, as the crisis continues desalination will become more viable (expensive or not, people need water to survive).
(or: you can't build a large number of solar power plants without affecting the market price of electricity)
Oh, wait. No it doesn't.
You spend a ton of energy pumping the seawater up to pressure, then you pass it through a turbine? Why on earth would you do that?
The capital cost of that is the cost of the generators + the cost of the desalination plants, and the desalination still probably isn't, even with the drought, the most valuable use of the power once you've built the generators.
> We could offset the electrical cost of desalination if the plants could help generate their own power.
We couldn't offset the opportunity cost of using the power for desalination rather than other uses that way, obviously.
> Over time, the plant will pay for itself
If its a permanent drought, maybe. Otherwise, that's doubtful. If the water isn't worth the electricity now, its an operating loss on top of the capital costs.
http://cleantechnica.com/2015/03/15/first-kind-wave-energy-f...