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This device was discussed earlier on HN and that article goes a little further into the design decisions for the device. (1) The focus is not efficiency or volu

This device was discussed earlier on HN and that article goes a little further into the design decisions for the device. (1) The focus is not efficiency or volume. It's compact, portable, robust, maintenance free. No filters, no high pressure components, suitcase size, able to use brackish water. They are not trying to solve industrial scale efficient desalination. They are trying to solve small scale portable desalination. You are measuring them against metrics they're not trying to achieve and it's no surprising they fail at this test. (1) https://news.ycombinator.com/item?id=31200793 https://news.ycombinator.com/item?id=31200793, also linked in the article for this post.

capableweb 4y ago
Not to mention that the perspective siliconescapee boils down to "You could buy X off amazon today" which is not even possible for loads of people, as Amazon doesn't operate in many countries, and there are plenty of countries where Amazon doesn't even ship to. Then we have the 10% of people who live in poverty and wouldn't be able to afford ordering it anyways. Those are the groups that would be most helped by a device with these characteristics as well (easy maintenance and low ongoing cost).
- Out_of_Characte 4y ago
  But this device has the exact same problem you're describing, is less efficient, costs more and requires power. Novelty is the only upside
  - Xylakant 4y ago
    The only device I could find on Amazon that fits the description of an inflatable desalination device is https://www.amazon.com/Aquamate-Solar-Emergency-Purification-Inflatable/dp/B004TOAELS/ref=zg_bs_3402151_55/146-1059240-0331150?pd_rd_i=B004TOAELS&psc=1 https://www.amazon.com/Aquamate-Solar-Emergency-Purification... and it reportedly produces between 0.5 and 2 liters of water per day. That’s great if you have none, but the device being discussed here produces substantially more. So it’s not just a novelty thing.
  - capableweb 4y ago
    Efficiency is less important in scenarios like tropical storms, drought, and infrastructure crises, or places where common western infrastructure is non-existent. Costs are also less important as they are cheaper over time as the costs of maintenance becomes lower. Places lacking infrastructure are also helped by outside organizations who donate knowledge and equipment. Considering that this device can be solar-powered (and these bespoke areas where infrastructure is non-existing generally are _very_ sunny), requiring power seems like a lesser problem.
- andrepd 4y ago
  At least 1.3 billion people live in poverty, much more than 10%.
  - ben_w 4y ago
    That depends on your definition of poverty; 10% of the world is in “extreme poverty” of $1.00/day in 1996 prices ($2.29 in 2021),
solarman1 4y ago
Uhh just letting you know a device that uses solar energy is not maintaince free and saying that it is would be naive at best and misinformative at worst. It's an even bigger problem in countries where accessibility for such parts does not exist or the expertise to maintain such equipment. In reality a project like this is rather useless and after a few years of use if it ever received any it would belong in the trash. But that's what most hackathons are in reality anyways.
- Xylakant 4y ago
  The device needs power, but solar is not a requirement. But you’re correct, nothing is ever absolutely maintenance free, especially if it contains moving parts. However, their envisioned use case is not “helicopterdump across the desert” but very specific use cases, often for people with technical skills: > This could enable the unit to be deployed in remote and severely resource-limited areas, such as communities on small islands or aboard seafaring cargo ships. It could also be used to aid refugees fleeing natural disasters or by soldiers carrying out long-term military operations. Whether they succeed in making a device useful these cases is a good question, but I consider it pretty dismissive that you characterize a 10 year research effort as “most hackathons”
  - solarman1 4y ago
    I see the majority of these grant styled competitions as just this, hackathons. Besides the prestige involved the majority of these inventions often prove to have little to no value to often not even doing as advertised. The way we incentive academic funding and research is backwards and often more than not broken at its fundamental core. It's compelled further due to these research rings broken into their own hierarchical technocratic groups.
helsinkiandrew 4y ago
But what are the use cases for a device that filters 0.3L of water an hour using 20W - that's still a fair amount of electricity? There are many ways to use the sun to desalinate that seem more appropriate to getting drinking water to humans in poor parts of the world. For example, this is another MIT project: https://news.mit.edu/2022/solar-desalination-system-inexpensive-0214 https://news.mit.edu/2022/solar-desalination-system-inexpens...
- Xylakant 4y ago
  According to them, their prototype does use 20Wh per liter and produces 0.3 liters per hour. It’s not 20Wh per 0.3 liters. That’s USB charger level of electricity, my 100 EUR foldable solar charger produces more on a good day. The interesting part about this is probably that even the prototype is fairly compact and weighs like 10kg and that they claim to be able to achieve that with brackish water. If they can prove that it’s as robust as claimed, that sounds like an interesting technology.

capableweb 4y ago

Not to mention that the perspective siliconescapee boils down to "You could buy X off amazon today" which is not even possible for loads of people, as Amazon doesn't operate in many countries, and there are plenty of countries where Amazon doesn't even ship to. Then we have the 10% of people who live in poverty and wouldn't be able to afford ordering it anyways. Those are the groups that would be most helped by a device with these characteristics as well (easy maintenance and low ongoing cost).

Out_of_Characte 4y ago
But this device has the exact same problem you're describing, is less efficient, costs more and requires power. Novelty is the only upside
- Xylakant 4y ago
  The only device I could find on Amazon that fits the description of an inflatable desalination device is https://www.amazon.com/Aquamate-Solar-Emergency-Purification-Inflatable/dp/B004TOAELS/ref=zg_bs_3402151_55/146-1059240-0331150?pd_rd_i=B004TOAELS&psc=1 https://www.amazon.com/Aquamate-Solar-Emergency-Purification... and it reportedly produces between 0.5 and 2 liters of water per day. That’s great if you have none, but the device being discussed here produces substantially more. So it’s not just a novelty thing.
- capableweb 4y ago
  Efficiency is less important in scenarios like tropical storms, drought, and infrastructure crises, or places where common western infrastructure is non-existent. Costs are also less important as they are cheaper over time as the costs of maintenance becomes lower. Places lacking infrastructure are also helped by outside organizations who donate knowledge and equipment. Considering that this device can be solar-powered (and these bespoke areas where infrastructure is non-existing generally are _very_ sunny), requiring power seems like a lesser problem.
andrepd 4y ago
At least 1.3 billion people live in poverty, much more than 10%.
- ben_w 4y ago
  That depends on your definition of poverty; 10% of the world is in “extreme poverty” of $1.00/day in 1996 prices ($2.29 in 2021),

solarman1 4y ago

Uhh just letting you know a device that uses solar energy is not maintaince free and saying that it is would be naive at best and misinformative at worst. It's an even bigger problem in countries where accessibility for such parts does not exist or the expertise to maintain such equipment. In reality a project like this is rather useless and after a few years of use if it ever received any it would belong in the trash. But that's what most hackathons are in reality anyways.

Xylakant 4y ago
The device needs power, but solar is not a requirement. But you’re correct, nothing is ever absolutely maintenance free, especially if it contains moving parts. However, their envisioned use case is not “helicopterdump across the desert” but very specific use cases, often for people with technical skills: > This could enable the unit to be deployed in remote and severely resource-limited areas, such as communities on small islands or aboard seafaring cargo ships. It could also be used to aid refugees fleeing natural disasters or by soldiers carrying out long-term military operations. Whether they succeed in making a device useful these cases is a good question, but I consider it pretty dismissive that you characterize a 10 year research effort as “most hackathons”
- solarman1 4y ago
  I see the majority of these grant styled competitions as just this, hackathons. Besides the prestige involved the majority of these inventions often prove to have little to no value to often not even doing as advertised. The way we incentive academic funding and research is backwards and often more than not broken at its fundamental core. It's compelled further due to these research rings broken into their own hierarchical technocratic groups.

helsinkiandrew 4y ago

But what are the use cases for a device that filters 0.3L of water an hour using 20W - that's still a fair amount of electricity? There are many ways to use the sun to desalinate that seem more appropriate to getting drinking water to humans in poor parts of the world. For example, this is another MIT project: https://news.mit.edu/2022/solar-desalination-system-inexpensive-0214 https://news.mit.edu/2022/solar-desalination-system-inexpens...

Xylakant 4y ago
According to them, their prototype does use 20Wh per liter and produces 0.3 liters per hour. It’s not 20Wh per 0.3 liters. That’s USB charger level of electricity, my 100 EUR foldable solar charger produces more on a good day. The interesting part about this is probably that even the prototype is fairly compact and weighs like 10kg and that they claim to be able to achieve that with brackish water. If they can prove that it’s as robust as claimed, that sounds like an interesting technology.