MIT engineers and collaborators developed a solar-powered device that avoids the salt-clogging issues of other designs. Engineers at MIT and in China are aiming to turn seawater into drinking water with a completely passive device that is inspired by the ocean, and powered by the sun. In a pap
Interesting, but very light on details about “cheaper than tapwater”. And the title is clickbait; the system they have is a small scale prototype and the developers only estimate that it would be cheaper than US tap water when scaled up. There is no further detail on costs in the article. Here is the extent of what it says:
The article doesn’t provide any more info on the costs than the above quote. Dunno if the actual journal article provides more detail; I don’t have access. But I would need to see a lot more about how they produced that estimate and how uncertain the estimate is.
You could always try and read the paper to get that information.