10 ms·

> The device worked for a week straight with no signs of salt accumulation, but we still don’t know exactly how long it could operate. Let’s maybe run it for a

by baxtr 4y ago

> The device worked for a week straight with no signs of salt accumulation, but we still don’t know exactly how long it could operate. Let’s maybe run it for a couple more weeks before we talk about it again?

deleted 4y ago
[deleted]
autoexec 4y ago
depending on how much clean water you get out of it in a single week it might still be worth it at $4 a pop even if it doesn't last much longer.
- political12345 4y ago
  not really: if average life is 2 weeks that means you need $100 per year for devices. Somalia gdp per capita is $500 (not taking PPP aince these will likely be imported). So 20% of anual income is quite high
  - nonrandomstring 4y ago
    It could save the lives of many people in a sudden water shortage until tankers arrive.
    - autoexec 4y ago
      Tech like this could even help some people in the US if their water becomes undrinkable for long periods of time due to some natural disaster or flint-like shenanigans.
  - zwirbl 4y ago
    Which ignores that it is 4$ per prototype and it works for longer than 1 week already
    - tekknik 4y ago
      from the article: “If it does prove durable, it could be a relatively cheap way to get freshwater to people in need of it.” The engineers are unsure of how long it will last and if it’s actually cost effective, yet there’s many HN comments here that seem to suggest they know better. Where are you getting your information that the rest of us are not privy to?
    - cyberlurker 4y ago
      $4 for 4 people too.
  - autoexec 4y ago
    The economics might not work well for everybody. Although international aid might ease some of the burden it may turn out to not be a good fit for Somalia, but it might be helpful for others. As drought and desertification worsens, even parts of the western US and Mexico might find some benefit in something like this.
  - tlamponi 4y ago
    It's for a family of four though, so 5% of annual income on average, meaning for 50% of people it's still worse. I'd also think that the GDP doesn't factor in international aid, so 25$ per year for the poorest could be still better than the current alternative (no idea on what that is, though).
- DoingIsLearning 4y ago
  I don't get what is the expected failure here? Can't salt accomulation be flushed away? I think for example reverse osmosis machine also have to constantly flush filtration debris away from the main membrane to maintain efficiency.
  - AstralStorm 4y ago
    That is one of the reasons big scale RO is impractical for desalination compared to upcoming redox tech. Not only is it slow, energy intensive, but also you'd always be running at reduced capacity. In indistrial usage, a lot of the salt is removed before hitting RO filter. That said, it exists right now and is well tested.
  - pbhjpbhj 4y ago
    Harvest the salt too, bonus!
- thematrixturtle 4y ago
  $204/year is approximately equal to the average GDP per capita for Burundi.
  - avierax 4y ago
    It may cost $4 in the economy where the study was conducted, it may end up costing more in less developed regions.
  - eurasiantiger 4y ago
    Clean water and sanitation access in Burundi is rapidly improving thanks to many international aid programmes, so perhaps this invention is not needed there—the country is bordered by freshwater lakes, after all. Your point still stands, but the $4 wouldn’t be paid by end users: it would likely be covered by these organisations, which would then be able to provide aid for a much larger population.
    - Tepix 4y ago
      Ideally it would be cheap enough that they can afford it themselves without having to rely on aid programmes.
    - wildmanx 4y ago
      And how sustainable is that solution?
      - eurasiantiger 4y ago
        More sustainable than having a growing population depend on surface water and open air defecation.
        wildmanx 4y ago
        That's not an answer to my question. I meant, how sustainable is it to keep depending on foreign aid? Obviously dirty surface water that does not suffice for the whole population is not sustainable. But in the long run, creating new dependencies on aid can't be the solution. Any long-term plan that involves foreign aid is a bad plan.
- HWR_14 4y ago
  It says it supplies 4x the amount of water a person needs (it supports a family of four). So, $1/person/week if it fails after a week and is not cleanable or fails because of a part that could be replaced
oxfordmale 4y ago
..and can it be mass produced at a reasonable cost. Scaling up a lab build product to an industrial scaled production line is a skilled profession. Not all products can make this transition.

by baxtr 4y ago

deleted 4y ago

[deleted]

autoexec 4y ago

depending on how much clean water you get out of it in a single week it might still be worth it at $4 a pop even if it doesn't last much longer.

political12345 4y ago
not really: if average life is 2 weeks that means you need $100 per year for devices. Somalia gdp per capita is $500 (not taking PPP aince these will likely be imported). So 20% of anual income is quite high
- nonrandomstring 4y ago
  It could save the lives of many people in a sudden water shortage until tankers arrive.
  - autoexec 4y ago
    Tech like this could even help some people in the US if their water becomes undrinkable for long periods of time due to some natural disaster or flint-like shenanigans.
- zwirbl 4y ago
  Which ignores that it is 4$ per prototype and it works for longer than 1 week already
  - tekknik 4y ago
    from the article: “If it does prove durable, it could be a relatively cheap way to get freshwater to people in need of it.” The engineers are unsure of how long it will last and if it’s actually cost effective, yet there’s many HN comments here that seem to suggest they know better. Where are you getting your information that the rest of us are not privy to?
  - cyberlurker 4y ago
    $4 for 4 people too.
- autoexec 4y ago
  The economics might not work well for everybody. Although international aid might ease some of the burden it may turn out to not be a good fit for Somalia, but it might be helpful for others. As drought and desertification worsens, even parts of the western US and Mexico might find some benefit in something like this.
- tlamponi 4y ago
  It's for a family of four though, so 5% of annual income on average, meaning for 50% of people it's still worse. I'd also think that the GDP doesn't factor in international aid, so 25$ per year for the poorest could be still better than the current alternative (no idea on what that is, though).
DoingIsLearning 4y ago
I don't get what is the expected failure here? Can't salt accomulation be flushed away? I think for example reverse osmosis machine also have to constantly flush filtration debris away from the main membrane to maintain efficiency.
- AstralStorm 4y ago
  That is one of the reasons big scale RO is impractical for desalination compared to upcoming redox tech. Not only is it slow, energy intensive, but also you'd always be running at reduced capacity. In indistrial usage, a lot of the salt is removed before hitting RO filter. That said, it exists right now and is well tested.
- pbhjpbhj 4y ago
  Harvest the salt too, bonus!
thematrixturtle 4y ago
$204/year is approximately equal to the average GDP per capita for Burundi.
- avierax 4y ago
  It may cost $4 in the economy where the study was conducted, it may end up costing more in less developed regions.
- eurasiantiger 4y ago
  Clean water and sanitation access in Burundi is rapidly improving thanks to many international aid programmes, so perhaps this invention is not needed there—the country is bordered by freshwater lakes, after all. Your point still stands, but the $4 wouldn’t be paid by end users: it would likely be covered by these organisations, which would then be able to provide aid for a much larger population.
  - Tepix 4y ago
    Ideally it would be cheap enough that they can afford it themselves without having to rely on aid programmes.
  - wildmanx 4y ago
    And how sustainable is that solution?
    - eurasiantiger 4y ago
      More sustainable than having a growing population depend on surface water and open air defecation.
      - wildmanx 4y ago
        That's not an answer to my question. I meant, how sustainable is it to keep depending on foreign aid? Obviously dirty surface water that does not suffice for the whole population is not sustainable. But in the long run, creating new dependencies on aid can't be the solution. Any long-term plan that involves foreign aid is a bad plan.
HWR_14 4y ago
It says it supplies 4x the amount of water a person needs (it supports a family of four). So, $1/person/week if it fails after a week and is not cleanable or fails because of a part that could be replaced

oxfordmale 4y ago

..and can it be mass produced at a reasonable cost. Scaling up a lab build product to an industrial scaled production line is a skilled profession. Not all products can make this transition.