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A comment on Solar-powered desalination device wins MIT $100K competition. Parent comment

Re:Solar-powered desalination device wins MIT $100K competition by kirrent on Tuesday May 17, 2022 @11:29PM (#31418950)
Without knowing more about this device it's a bit hard to make a true comparison to existing marine RO devices but there are a few reasons I've been following with (skeptical) interest:

- Low volume - RO devices don't scale down well. The Katadyn 40E is the smallest watermaker I can find and it produces 6l/h. This is an insane amount of water that I have no use for. 10l a day would be enough for two people. Unfortunately there aren't cheaper and lighter options available.

- Storage - No pickling would be really nice.

- Membrane - Not needing to replace membranes would also be nice.

- Efficiency - I don't care too much about efficiency because most of the time during the day we have plenty of power from 400W of solar panels sized for days and days of cloud. That said, smaller RO devices also have poorer efficiency, e.g. 9Wh/l in the 40E. Other results in the literature suggests there could be plenty of room left to improve in efficiency from the MIT prototype.

Depending on cost, I think there's a niche for something that addresses the lower end of the market in watermakers.

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Re:Solar-powered desalination device wins MIT $100K competition by unwind on Wednesday May 18, 2022 @03:23AM (#31420095)
As someone who uses a kitchen more than a galley (i.e. I'm a land crab), I had to look up if "pickling" had a special meaning here.

It turns out to be kinda true, nobody is putting components of their watermaking system [1] in acidic solution for preservation and flavor, but they are putting them in sodium metabisulphite solution and that chemical seems to be useful for disinfecting and so on [2].

[1]: https://www.openoceanwatermakers.co.nz/pickling-your-system....

[2]: https://en.wikipedia.org/wiki/Sodium_metabisulfite

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Re:Solar-powered desalination device wins MIT $100K competition by salty_biscuits on Wednesday May 18, 2022 @06:47AM (#31421171)
If you can lower the transmembrane pressure you will get less output for less power and no fouling of the membrane. The economics of consumer choice drive design towards higher outputs and fouling.
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