Yeah, if I was gonna build a desalination plant built to use <$0 cost electricity, I would essentially build a giant (distillation) still. I'm not a process expert in flash desalination, but it looks similar to (maybe identical to) a still.

Just a big resistor in a big tank (or pond), a big fume hood and coil to another tank. Capital cost can probably be minimized a whole lot.

Seeing as "boiling the ocean" is the standard business phrase used to dismiss an overly ambitious and likely impossible to execute plan [1], there would be something beautifully ironic about a startup whose explicit goal is to solve a real world problem by literally boiling the ocean.

[1] http://workingwithmckinsey.blogspot.com/2013/11/Avoid-Boilin...

You can use sun light directly for that. Just paint your boiler black, maybe concentrate some sunlight with cheap mirrors.

This works well when you have a lot of sun. Instead you might have a lot of wind.

Also, you only want to run the desalination plant when the electricity price is too low ("below zero" with the transmission included), so you want generators for most of the time, when you actually sell the power.

Yea but not at night.

The entire point of this discussion is to figure out how to use electricity only during the day.

Even for RO the big expenses are running the pumps and fouling of the membrane, caused by high concentration of salt due to the high pressure used. If you weren't worried about throughput they last a very long time. You could use cheap electricity to pump water to a reservoir and use gravity as the pump for cheap RO. It isn't any different from any other source of off grid storage.