I've wondered why desal hasn't also paired up with ocean mineral extraction. It seems like the two would go well together.
Even when talking about RO, you'd think diverting all or part of the brine water for evaporation would reduce the cost of extraction. You'd have water with more concentrated minerals which would give you a higher yield per evaporation cycle.
Also, it'd be nice if we could bring back magnesium extraction from ocean water.
I wonder what can have better potential efficiency, a classic solar panel and an electric boiler/dryer, or these devices?
Fundamentally, a direct device has fewer transformation losses.
That is assuming your boiler uses resistive heating to generate heat and not heat pumps to move heat.
Solar desalination looks pretty good in terms of efficiency. The problem is that the solar energy must now be collected at the shoreline. This means that a lot of coastal real estate gets turned into a desalination plant. Alternatively, you transport the water, but pumping seawater requires corrosion and fouling resistant materials throughout the system.
Why would you waste sunlight on light->electricity->heat conversion?
Just do direct evaporation like it's been done for thousands of years. If you don't like brine, leave it to dry out too.
If there is not enough sunlight, use direct nuclear heat.