Battery-free solar desalination system produces up to 5,000 liters of water per day
Battery-free solar desalination system produces up to 5,000 liters of water per day/Sistema de desalinización solar sin baterías produce hasta 5.000 litros de agua al día (@mauromar)
A useful product can be nice, but I wouldn't call this patent uplifting news.
It'll be uplifting when its use is widespread.
Well if we could get 44 million of these going 24/7 we could counteract the ice caps in Greenland melting.
Hang on a sec. I'm trying to understand something here. Lets say there is a huge amount of salt from all the processing, is the salt so bad that it cannot be consumed, or there is just too much salt that it exceeds consumption?
It's just a lot of salt. Seawater (on average) is 3.5% salt. So for 1kg of water (aka 1 liter) you get 35 grams of salt. For 5 thousand liters, thats 175kg of salt. While we do use salt for industrial purposes, that salt is usually treated and chemically processed for sanitary reasons. Given the average person uses 310 liters of water a day (drinking, cooking, cleaning, ect...) 5,000 liters gets you slightly more water than 16 people are going to consume in a day. And 175kg of salt is way more than 16 people are going to use in a day. Now figure this system runs all year round, and we have 63,000kg of salt. Just so 16 people could drink desalinated sea water all year.
There are a number of theories put forth in recent years how best to desalinate sea water for drinking water and disposing of that salt, most of them involve dumping it in the desert, burying it in old mines, or possibly deep sea operations where salt concentrations are already too high for most life to exist, so adding salt to those regions won't have a ecological impact and it's possible for currents to spread that excess salt over a wider area.
Every one of these options has downsides, but we do need water to live and oceans are a vast source of water we aren't really tapping so you can see the desire to utilize them when majority of the global population lives within a hundred km or so of a coast line.
Thanks for taking your time to explain! Guess its now how risk adverse are we, and judging by that, not really are we?
You have to put it somewhere. And salt tends to be bad for its surroundings. Even if you put it back into the water, You'd have to spread it very far for it to get diluted enough to not be a problem
And I would have to guess that the resulting salt is not remotely clean enough for human consumption. So you'd have to process it before you could sell it (if there would even be a big enough market)
Why battery free?
Batteries are cheap and great.
Oh its refried MIT garbage. Ok.
Extra, expensive layer of maintenance. This isn't just your average 5V1A AA battery; even the batteryless thing needs 100Wh.
Oh its refried MIT garbage. Ok.
What do you mean refried? What about MIT?
Agreed, got very MIT 'WaterSeer' vibes from this...
I can't find any relation between WaterSeer and MIT. And unlike WaterSeer, this was published as a peer-reviewed Nature paper in Oct 2024.
Its its coming from MIT, it deserves an extra pass of scrutiny.
WaterSeer was initially somehow related to some part of UC Berkeley, rather than MIT.
You may be thinking of this device: https://www.cell.com/joule/fulltext/S2542-4351(20)30444-X
... Or the metal oxide framework predecessor to it, or the newer thing that uses some sort of gel.
I'm not aware of a commercial product based on this work.
Batteries are not cheap, especially on industrial scale. And most batteries are not ecologically friendly. It makes far more sense to put all the power solar panels produce during the day to immediate use for maximum efficiency, there is no form of battery that exists that doesn't have some kind of efficiency loss.z
Putting a battery on this is like building a water tower in your front lawn that only feeds your sprinkler, and you're only filling it from a hose. You don't really get any benefit out of it and it's just easier to run the hose right to the sprinkler anyways.
Approx 35 grams of salt per litte. 35 g x 5000 litres per day is about 385 pounds of salt everyday. This is the problem with desalination no one discusses.
On the low end people use around 300 litres a day. So this is only enough water for 16 people. When you start scaling this it really becomes clear.
Let's say you wanted to provide LA with water from desalination. At around 23 pounds of salt from 300 liters of water per person with LA population being 3.8 million that would make 87 million pounds of salt... wait for it... per day!
Sure you can put it back into the ocean, but that is not good for sea life at all. Not to mention all the energy needed to pump it back if that is what you choose to do. I don't think sequestering is an option either.
If you have a conveniently located valley you're not using, you can make a new great salt lake for a few years. 87 million pounds of salt sounds like a lot, but a cubic mile of salt weighs approximately 9 trillion metric tons, or about 20 quadrillion pounds, or over 600 years of salt at 87 million pounds per day.
I'm sure there are a few people (very few) who would disagree, but a quick glance at a topo map shows Shelter Valley as a possible target for a strategic sea salt reserve deposit that could serve the area for hundreds, perhaps thousands of years. San Francisco bay looks like they have salt ponds in what could otherwise be valuable real-estate.
Here I thought it was an oversized fish bol, upside down, using the sun to evaporate water.
Silly me.
Do you come with the desalination system? Heh heh.
You can make your own:
https://patents.google.com/patent/US20170050868A1/en
There's still a battery, but its storage for the solar pannels, unless they're using a different method.
The energy part of this one is different:
I guess you could, but the EDI units to clean water aren't cheap, sheesh.
https://www.alibaba.com/product-detail/EDI-Water-Treatment-System-Electrodialysis-EDI_60755412999.html
If they wanted to have people make their own, why would they patent it?
If you want everyone to have it, you patent, then charge nothing to license it.
If you don't patent it, then a corporate patent troll will come in, patent it, charge an inordinate amount for the license, then bury you in paperwork with a lawsuit so you can't fight back. Effectively killing the tech.
sometimes you want some sort of control, or trade… like, (as much as like everyone else hates them this is the best example i can think of) tesla holds a bunch of patents and says people are free to use them, but if you do you can’t sue them for patent infringement: they still have some control