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.
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)
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.
I think it is important to keep in mind how much energy moving 87 million pounds of salt a day would take. Unless this valley was extremely close it would be prohibitive.
I do think you have a decent idea though if we had to use desalination and didn’t want to dump it right back into the ocean.
The real answer is to dilute the salt back into the ocean, but even the cost of transport - whether by truck or rail or pipeline - a hundred miles and +3000’ of elevation is likely less than building and maintaining a system that distributes that salt widely enough in the ocean to have negligible ecological impact at the points of dispersal.
A thousand smaller desalination plants spread along a hundred miles of coastline each distributing 87 thousand pounds of salt per day (basically: one pound per second) would be more feasible for ocean discharge than anything you might try to do from a single point. The system would also be much more robust / less prone to critical failures. ~10% of the plants might be offline at any given time while still providing full required capacity.
Looking at those numbers, I would propose something like 500 plants, no two closer than 1000’ from each other along the coastline, each distributing up to three pounds of salt per second in a 6" outflow pipe at least 500’ offshore that’s carrying 100 gallons per minute of water with that salt dissolved therein. The discharge could be through a series of 100 1" holes spread 1’ apart. I’m sure there would be local ecological effects, but in most areas they should be minimal by the time you’re 200’ or more down-current from the outflow.
Compared to treated wastewater discharge, I think the salty water discharge would be much less impactful. There’s probably some opportunity to combine treated wastewater with the salty discharge to further treat the wastewater, though I wouldn’t want to do that in ALL the salt discharge plants (you’d want some to study the salt impact alone.)
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:
Because the system can quickly react to subtle changes in sunlight, it maximizes the utility of solar energy, producing large quantities of clean water despite variations in sunlight throughout the day. In contrast to other solar-driven desalination designs, the MIT system requires no extra batteries for energy storage, nor a supplemental power supply, such as from the grid.
if(true)
MIT doesn’t lie as often as some sources.
I guess you could, but the EDI units to clean water aren’t cheap, sheesh.
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.
No, that’s not how open source hardware works.
You copyright it (free) and publish online with a copyleft license.
You would absolutely win in court without the patent. Just point to the publishing date on GitHub. Then you sue them for filing a blatantly fraudulent patent.
How many suits for these kinds of blatantly fraudulent patents have actually been won? And lost?
Patents does not have defensive uses, only offensive.
You beat patent trolls by demonstrating you published first.
no defensive uses
Says someone whos never blocked an assassin’s ninja star with a binder full of patent paperwork. There was also some incorporation stuff in there, but not enough to have worked with that alone.
Clearly you lack real experience in the field.
They can be defensive in a roundabout way like the x86/amd64 patents
Only against practicing entities, and if you have enough cash reserves to deter them with legal expenses.
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
Yes, Tesla is a good example. Only evil companies with malintent file patents.
Here I thought it was an oversized fish bol, upside down, using the sun to evaporate water.
Silly me.
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.
Yeah I’m sorry but I’m right out of the gate calling this a scam.
I’m not saying it is a scam but I’ve seen so SO many “free drinkable water!!” scams built by scamming absolutele idiots, that I’m first assuming this is bullshit until I’ve seen the actual designs and products for real
Again, not having read the article: if this is something with “please fund us, we will make it awesome” then you better close that wallet fast as you’re about to be scammed.
It doesn’t matter if it’s university backed or not, even Stanford and MIT backed scam projects that first graders could have identified as a scam and turned up nothing
Unless they have a fully functioning system that produces at least 5000 liters of drinkable water per day, every day, this is a scam. I’ll read the article after and update.
Having said all that, depending on where you are that can support a village or a single village idiot.
Edit: having read the article, I’m still staying on the “scam” part. For one: “In addition, unlike other systems, this one does not require batteries to store energy nor does it depend on an external electrical grid.” is bullshit. If you want it to run at night you either need batteries, the power grid or a little garden gnome furiously cycling to power a generator. As said before: that it’s backed by MIT says little to nothing
Your calling it a scam right out the gate. But you’re not saying it’s a scam. And you’re not reading the article.
10/10
Tell that to the Nature journal and the thousands of scientists who’ve read a paper on this specific system design since its submission and then its publishing in October 2024.
If you want it to run at night you either need batteries, the power grid or a little garden gnome furiously cycling to power a generator.
Simple: It doesn’t run at night, as mentioned in the article. Also mentioned is this is actually more efficient than having a battery to also run at night.
You contradicted yourself in your opening two sentences. I’m going to assume the rest of your comment is just as confused and skip it.
During six-month trials in New Mexico, the system harnessed 94% of the energy generated by the solar panels, maintaining a constant production of drinking water even with fluctuating weather, producing up to 5,000 liters of drinking water per day without the need for batteries or an external power source.
It looks like it’s just a test/demo of plumbing reverse osmosis desalination directly into solar power. I’m guessing there is mechanical energy buffering in the system, meaning that batteries aren’t required to smooth power flow out.
For me, the question of how innovative it is comes down to kW input per gallon output. Doesn’t matter to me if the power in is coming from solar, coal, nuclear, or hamsters in generator wheels, the efficiency of the system still comes down to power input and space required.
Do you come with the desalination system? Heh heh.
Why battery free?
Batteries are cheap and great.
Oh its refried MIT garbage. Ok.
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.
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?
They’re probably upset that MIT refused to let someone attend the graduation because of their pro-Palestinian views, and therefore they make dumb statements about MIT’s education and contributions.
saying someone’s statement is dumb is very provocative
Then don’t be dumb.
I assume you stand with Israel?
What do you mean refried? What about MIT?
MIT is in the business of marketing MIT, and they are damn good at it. And I do think the people doing this work should be highlighted. However, it ends up being almost exclusively hype.
Its a trope specifically related to MIT.
Every university markets itself including the research university. Can’t we just accept that battery-free desalination is really cool and efficient? The fact that they were research students of MIT had not registered any land in my mind until you pointed it out.
I understand your motivation and desire to not let the morons go un-opposed, I appreciate what you’ve done, but it’s time to leave the troll in it’s cave. The ogre will not turn to stone if it feels the touch of sun unfortunately. Shine your brightness in places it’ll be appreciated.
I get that you simply don’t understand whats being said. You’ll figure it out eventually.
Agreed, got very MIT ‘WaterSeer’ vibes from this…
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.
UC Berkeley
I stand corrected, you are right. All the links I bookmarked 404 now but it was a UC Burkely funded project.
https://scet.berkeley.edu/vici-labs-collider-project/ https://scet.berkeley.edu/waterseer-collider-winners-announced/
Thank you for correcting the record.
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.
Tell me more about how you don’t understand technology or politics.
I understand both, excellently.
Could you explain why https://pubmed.ncbi.nlm.nih.gov/30723834/ is wrong in saying batteries are a significant barrier to deploying the solar-powered, then?
2019 article about battery technology; meanwhile, we’re literally living in a revolution driven entirely by the battery technology (and pricing) that the article says shouldn’t have happened: quite simply, they got it wrong.
https://ourworldindata.org/grapher/average-battery-cell-price
The price decrease and performance increase in battery technology has made them disproportionately more valuable than we expected them to be.
Go find a 2025 article if you want to support your previous point.
The fact is batteries got better and cheaper, both, faster than we expected them to. Solar is already more than efficient to overwhelm our storage capabilities. Its a better investment to design and build with batteries, almost always. The additional complexity at this point is minimal.
If the technology is so great, why not just slap in some batteries and have it run 24/7? Batteries are so cheap there is no reason not to.
They are not that cheap. I don’t know what age you think this is, but batteries and replacement is a huge investment. It is the main reason people sell their cars because the cost is so prohibitive.
Your statement about understanding technology is bull.
The battery price revolution started way before 2019. There’s nothing unprecedented about today’s battery prices from the PoV of 2019. In fact, your own data says that in fact the price decrease has been slowing down: Besides the visible fast decrease between 2014 and 2017, prices-per-kWh were about $128 in 2018, $120 in 2019, $110 in 2020, $99 in 2021, and then pandemic inflation spiked it and three years later it only managed to decrease to $78 in 2024. No, I don’t think battery prices are falling faster than we expect them to.
And here’s an article from 2023: https://www.sciencedirect.com/science/article/pii/S0301479724010430
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