It will be like that until 2pm or so, which gives 4.5 hours to do useful stuff either for free or very cheap (as obviously, the prices will go somewhat up, if demand increases).
Desalination costs are dominated by energy costs. And I am making a point that California is in a perfect position to solve its water problems with the excess of solar capacity by using it to desalinate ocean water during the time of day when energy is essentially free.
Yeah, desalination is perfectly aligned with solar energy availability both on a daily and annual cycle: More water needs during the day, more sun during the day. More water needs during the summer, more sun during the summer.
I honestly fail to understand what you mean. Care to rephrase / elaborate?