I'm not sure what they're attempting to describe in the article but so far seems to me like a child's toy compared to a proper multi-stage flash distillation plant (which uses multiple stages and decreased pressures at each stage to massively decrease energy requirements) -- and even those should use more energy than reverse osmosis plants.

Getting water from the sea up to the desert would be a huge challenge in California, and right on the coast isn’t very sunny for most of it.