Solar-powered desalination device wins MIT $100K competition

https://news.mit.edu/2022/100k-competition-nona-0516

by rawgabbit • 4 years ago

288 149 4 years ago

news.mit.edu

kaycebasques• 4 years ago

Exciting! This wouldn't help with problems like lead in the water, would it?

MichaelApproved• 4 years ago

I think it’s meant to provide an emergency source of water for drinking.

You wouldn’t want to use this for a large population for a prolonged period of time because you’d have trouble disposing of all the salt waste.

Figuring out how to handle the salt byproduct is a critical part of long term desalination.

thghtihadanacct5• 4 years ago

Maybe we can place the effluent at the base of a glacier so it buffers the fresh water coming off the melting glaciers and keeps the ocean running? /s

beaned• 4 years ago

Can you pack it and sell it?

Red_Leaves_Flyy2• 4 years ago

How much salt are we talking? A large portion of the country coats all paved surfaces with it during and after every snow/freezing rain. Shut down the salt mines if need be.

izzydata• 4 years ago

Put it on a rocket ship and fly it into the sun of course.

worldsayshi• 4 years ago

I don't see what the issue would be of just dumping it back into the ocean if you find no better use for it?

barathr2• 4 years ago

While this is a nice project for emergency and remote uses, what we really need re: desalination in places like California (and other variable / dry climates) is large-scale desalination tied to opportunity power (such as curtailed grid power).

With each passing year there's going to be more and more solar on the grid, and it's going to be hard to soak up that power during the daytime peak. Desalination matches the solar supply curve perfectly: there's more water demand during the day, and there's also more water demand during the summer when there's also more sun. It's the ultimate dispatchable load.

elihu3• 4 years ago

..also, water storage is fairly straightforward, so the water usage peak doesn't have to exactly track with the daily solar power production peak.

hardwaresofton2• 4 years ago

depending on how you build the storage, you could also use the excess water for power, no? Some sort of gravity battery setup.

laurencerowe2• 4 years ago

Do we really need expensive desalination in California? Domestic water use only accounts for 20% of demand and desalination seems unlikely to ever be cheap enough for agricultural use (the remaining 80%.)

barathr2• 4 years ago

True, though there's a question of whether there will be demand to keep up those ag uses as water becomes more scarce generally (I could see it going either way).

Electricity is something like half of desalination's operational cost, and we're already in a situation where the price on the grid goes negative (or is curtailed) during solar peaks and more and more solar is being added to the grid each year. So power for desalination is going to be near free in the coming years. (Whereas for other less flexible loads, electricity isn't likely to get cheaper quickly, since we have to either have storage or use gas plants.)

sammalloy2• 4 years ago

Do we really need expensive desalination in California?

It’s a good question, and it’s been discussed quite often in recent media sources for the past two weeks due to the rejection of the proposed Poseidon plant in Huntington Beach.

The honest truth is you could probably argue for both sides. Realistically, it’s cheaper and less environmentally harmful to promote non-desal measures, but not as easy to see quicker and observable benefits. The problem with the latest proposal was that it had a lot of problems, and the company behind it has a paper trail of small scale disasters in its wake (see the failure of the Tampa Bay facility, for example).

I personally believe that this is the kind of project that could benefit from a closer partnership between the government and private industry. From what I can tell, the technology is mature and feasible, but every time someone tries to design and implement it in the states, they seem to drop the ball.

I would be curious to see the record of success of other large scale projects outside the US. I’ve heard about the benefits and risks of the plants in the Middle East and elsewhere, but I don’t know the details.

ransom15382• 4 years ago

Yeah! California could fix the water issue by restricting agricultural use water. That way, California could finally kill off it's agricultural production. This will ensure farmers will move to other states and turn to the plentiful supply of hard drugs. This seems exactly what California will do. You would think California politicians might make a good decision -- EVEN by mistake once and while -- but NO. How is that train from LA going?

https://www.reuters.com/world/us/california-staff-report-rec...

s0rce2• 4 years ago

Other than a few coastal places like Marin and Sonoma that aren't on the state water project I think the answer is no. The resulting water will be too expensive. It would be cheaper to pay farmers to stop growing inefficient and largely unnecessary crops (pasture grass, alfalfa) or to move to more efficient drip irrigation. As you said, the domestic use is so low and ag users wouldn't pay for desalination when there is actually a fairly sizable (although possibly dwindling) source of water available.

kodah2• 4 years ago

I've posted about this on here before but the remaining 89% actually isn't just agriculture, though that is a Californians favorite scarecrow.

https://en.wikipedia.org/wiki/Water_in_California#Uses_of_wa...

Water use in California is divided into approximately 51% for environmental uses, 39% agricultural use and 11% urban uses, though that varies considerably between regions and between wet and dry years.

Melting_Harps2• 4 years ago

Do we really need expensive desalination in California? Domestic water use only accounts for 20% of demand and desalination seems unlikely to ever be cheap enough for agricultural use (the remaining 80%.)

If you like to eat, yes, you do. I still cannot fathom what distorted minds most transplants possess: California was and is an Ag state, it;s a fundamental part of it's culture it also feeds most of the US with its produce/fruit and exports it's surplus all around the World in surplus commodities.

Yes, stricter water preserving techniques are required for Ag, this recent budget surplus should go towards that as well as desalination to replenish aquifers and reservoirs/quarries after decades of an unsustainable population growth. This recent COVID exodus needs to go on for decades for the population to just return to the norms of the 70-80s.

You guys that write this kind of misinformed responses are so delusional, you cannot eat apps or drink code when you're hungry: and I can assure you will be the first to break when you haven't been fed for a few days or have to ration food/water since you've been accustomed to a lifestyle that simply doesn't reflect reality. And I highly doubt you can do any level of manual labour in order to feed yourself, either.

Get real, water conservation methods all around needs to be enforced BY EVERYONE! AG is guilty of exploiting loopholes when CA water laws were written to serve prospectors, and they should be taxed for over-useage and incentivize them with grants to utilize drip irrigation systems etc... but if you really want to solve this issue, which most of you won't agree to, is remove Farm subsidies: this will force farmers to cut down on these practices to make alfalfa or soy in the Central Valley for export to China that is only profitable because the State subsidies this horrific business model, it in turn will make food get even more expensive, which if you look at it in terms of net income is the historical norm: ~15% of total net income [0].

Food security is a matter of national security for a reason, it's used as a reliable weapon in warfare and has been a reason why most of humanity has gone to war in the first place, and if you like to keep civilization operating it's absolutely critical.

0: https://www.thevintagenews.com/2020/05/07/grocery-store-pric...

badrabbit2• 4 years ago

Nuclear power to the rescue (again! Lol) use excess heat from nuclear power generation and the water that gets steamed anyways for cooling and desalinate it. The brine problem can be solved by not desalinating endlessly but using desalination to create lakes and dump the brine in the desert where nuke waste is buried.

stubish• 4 years ago

Mixing corrosive saline and nuclear waste storage facilities is probably not the best idea.

deadmutex• 4 years ago

One of the big challenges: convincing people to drink water that was desalinated at a nuclear power plant.

wbl• 4 years ago

We already have a pool of brine in the desert.

ncmncm8• 4 years ago

Nuclear power is, as always, overwhelmingly more espensive than the alternative, solar. We have a great deal of desert in California, with plenty of sunshine, and evaporating only when the sun is out is fine.

You wouldn't even need enclosed evaporation containers; let the wind carry the moisture to the mountains, raining into existing reservoirs.

elihu3• 4 years ago

The article links to another article with a lot more detail about the system:

https://news.mit.edu/2022/portable-desalination-drinking-wat...

20 watt hours per liter of water seems to be the important number.

I wonder if this system would also work for concentrating brines, if one's goal wasn't to produce clean water but rather extract certain valuable minerals, like lithium?

WaitWaitWha• 4 years ago

Slight correction

Their prototype generates drinking water at a rate of 0.3 liters per hour, and requires only 20 watt-hours per liter.

So it takes 3+ hours to make a liter, using 20Wh.

jakear• 4 years ago

So? It's trivially paralleled, this isn't a case of 9 women making a baby in a month. Just run three devices, get 1 liter in 1 hour with 20 watts.

thghtihadanacct5• 4 years ago

Lots of gold in that water too. Mostly salt tho

elihu3• 4 years ago

I figure there must be a lot of things in sea water that might be valuable, if only you could concentrate them. Or in brines that are extracted from underground, like how some lithium is currently mined if I understand correctly.

itissid• 4 years ago

Concentrated Brines

Like the ones NASA has on the shuttle https://www.nasa.gov/feature/new-brine-processor-increases-w... right?

zo1• 4 years ago

Is it just me or does this kind of thing just feel so weird and out of place:

"The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity."

thombat• 4 years ago

For version 2 they're adding themes for the social media icons

fennecs• 4 years ago

Why are there so many water from x devices from MIT. Water from air, water from salt water etc. Is this all they do lol? Is there a group of people responsible?

junon• 4 years ago

Because it's a continual issue in the world, perhaps?

buescher• 4 years ago

Yes. There's government money for "water and sanitation issues". NGO money too, but most of that is government money.

All of which issues have conventional solutions, but it's hard to assert you have a breakthrough with an incremental improvement to conventional solutions. And most of the time, deep incremental improvements require a lot of practical domain knowledge of the sort academics and especially their graduate students don't have.

You can probably still win an award for proposing using a lawn roller, as described in U.S. patent 1538550, filed in 1924, for transporting water in developing countries. If you're the right sort of person. More than one person has.

Actually figuring out how to bring sewers and water treatment and indoor plumbing to people in developing nations, that's too hard, too much like work, undeserving of your unique genius.

plaguepilled• 4 years ago

This is legitimately uplifting. I've lived without drinkable water on tap for just a few weeks, and its not a fun experience.

Huge props to MIT and the research team for this.

WalterBright3• 4 years ago

I don't get it. Survival books show how to make a solar still with a plastic tarp, cup, straw, some rocks, and a hole in the dirt.

turtledove2• 4 years ago

How much water does that produce, and how much human labor must go into collecting it, and how well does it work in windy or cold conditions?

WalterBright3• 4 years ago

How much water does that produce

Depends on how big it is, and the amount of sunshine

how much human labor must go into collecting it

That's what the straw and cup is for. You put your lips around the straw and suck.

how well does it work in windy or cold conditions

As well as evaporation works on windy or cold days. It won't work when it's raining, but then you wouldn't need it when it's raining.

BTW, why would wind affect it?

Cthulhu_4• 4 years ago

A good survival book will also tell you that just one of those won't produce enough water for one person to survive on.

WalterBright3• 4 years ago

You can make more than one. You can make a larger one.

cestith2• 4 years ago

Solar stills can be simpler or far more complex than that, too. One design's just a milk jug and some aquarium tubing. Others are shed-sized or barn-sized construction projects.

https://news.ycombinator.com/item?id=31422582

siliconescapee• 4 years ago

This is incredibly inefficient compared to existing desalinization devices. My boat has a watermaker that uses 4w/liter and it isn't even state of the art. This is 5x less efficient. It is also incredibly low volume.

There is novelty in the method, and in not using filter mediums. But those differences aren't going to matter if it isn't an order of magnitude more efficient. You could buy an inflatable evaporative device off amazon today to desalinate seawater that makes far more water with no electrical input at all.

I'm a bit saddened to see this show up on HN after it made the rounds on FB groups a month ago, where it was debunked. The world has fresh water problems and desalinization at scale with higher efficiency would be a huge unlock. That is exciting. But I'm not sure why this particular approach is getting attention given it underperforms so badly. Except maybe that the letters MIT and a lot of journalists that don't care as long as you clicked.

Commodore63• 4 years ago

Not using filters is huge! RO watermakers are really sensitive to poor quality water. Algae from last year's heat wave knocked out a lot of watermakers in Pacific waters.

sitkack• 4 years ago

From the paper

The portable system desalinates brackish water and seawater (2.5−45 g/L) into drinkable water (defined by WHO guideline), with the energy consumptions of 0.4−4 (brackish water) and 15.6−26.6 W h/L (seawater), respectively.

So it consumes 26Wh/L turning nasty lowtide into drinkable water with no filter.

A 300W solar panel could then produce 10L of water per hour for probably 5 hours a day. 50L a day per panel. That is amazing!

kirrent• 4 years ago

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.

unwind• 4 years ago

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

salty_biscuits• 4 years ago

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.

adrianN2• 4 years ago

I wonder how much energy it takes to make the RO membranes.

Xylakant5• 4 years ago

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, also linked in the article for this post.

capableweb2• 4 years 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).

solarman12• 4 years 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.

helsinkiandrew2• 4 years 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-inexpens...

beefield• 4 years ago

watermaker that uses 4w/liter

I think you have a typo there, but I am not sure what you mean. Maybe 4Wh/liter? (Knowing nothing about desalination, that sounds low, though)

danbruc2• 4 years ago

Seems about right, the Katadyn PowerSurvivor 40E/12 V mentioned in another comment is 12 V, 4 A and 5.7 l/h, i.e. 8.4 Wh/l.

helsinkiandrew2• 4 years ago

Yes, this device (first I found from google) produces 100L/hour using 400 Watts

https://www.nauticexpo.com/prod/schenker/product-23417-55567...

Cthulhu_4• 4 years ago

If it doesn't use filter mediums, where does the salt and contaminants go?

Xylakant5• 4 years ago

Even devices that use Reverse Osmosis usually don't aim to catch all contaminants in the filter - they use a membrane/filter to separate the clean water output from a waste water stream that contains the contaminants/salts in higher concentration. This device effectively tries to replace the filter/membrane with an electrical current:

From https://news.mit.edu/2022/portable-desalination-drinking-wat...:

their unit relies on a technique called ion concentration polarization (ICP), which was pioneered by Han’s group more than 10 years ago. Rather than filtering water, the ICP process applies an electrical field to membranes placed above and below a channel of water. The membranes repel positively or negatively charged particles — including salt molecules, bacteria, and viruses — as they flow past. The charged particles are funneled into a second stream of water that is eventually discharged.

relaxing2• 4 years ago

Down the drain.

darksaints• 4 years ago

I don't know why some people are so obsessed with efficiency. Efficiency is, at best, one attribute of many which make something practical. We have had engines that are 50% thermally efficient for decades now, but no automaker has attempted to produce them because they are impractical in hundreds of other ways.

Not only would I buy this for my boat, but I would replace my more efficient spectra watermaker with it. Less noise and less maintenance are massive advantages.

konschubert• 4 years ago

Yea.

- "This energy storage is only 30% efficient".

- "Yes but it's dirt cheap and so is solar peak power."

ncmncm8• 4 years ago

Right. Panels are so cheap now that, unless you are limited in how many panels you can physically install, lower efficiency just means another panel. Even then, maybe you cant a pair of them in place of one so one picks up morning light, and the other afternoon.

dragontamer• 4 years ago

I'd imagine that most beachfront properties have basically unlimited water, but are instead throttled by electricity costs.

Output water vs input water efficiency (20% in this case? 1-liter output from 5-liters input saltwater) matters in some cases, but not others. Since we all live in different terrains and locations, some inventions will be useful in some areas, while other inventions are useful in others.

ncmncm8• 4 years ago

You can imagine that, but a solar panel is cheap if it delivers 50L/day.

sambroner• 4 years ago

Congratulations to Bruce & Team! Always exciting to see a classmate building cool stuff.

demadog• 4 years ago

$100k? Most SV engineers could self-fund that. Why not make it $1m+?

s1artibartfast5• 4 years ago

Because it is a school project and not subject to any realistic assessment of commercial viability or innovation.

noisy_boy2• 4 years ago

The winner of this year’s MIT $100K Entrepreneurship Competition is commercializing a new water desalination technology.
The company has already developed a small prototype that produces clean drinking water. With its winnings, Nona will build more prototypes to give to early customers.
The company plans to sell its first units to sailors before moving into the emergency preparedness space in the U.S., which it estimates to be a $5 billion industry. From there, it hopes to scale globally to help with disaster relief. The technology could also possibly be used for hydrogen production, oil and gas separation, and more.

I think it is a bit beyond just being a school project (and I sincerely wish them all the best).

s1artibartfast5• 4 years ago

Certainly more exciting than the second place prize

Inclusive.ly can scan a range of communications and make suggestions for improvement. The algorithm can detect discrimination, microaggression, and condescension, and the founders say it analyzes language in a more nuanced way than tools like Grammarly.
The company is currently developing a plugin for web browsers and is hoping to partner with large enterprise customers later this year. It will work with internal communications like emails as well as external communications like sales and marketing material.

closewith• 4 years ago

That’s horrifying.

Biologist123• 4 years ago

“We make our tools and then our tools make us”. One can see the possibly good (or commercial) intent in this - but it also creates the realisation for the thought police to be inserted into AI. A relevant quote from my clippings:

"we have become so deeply habituated to the traditions of written language – our minds are quite literally shaped by them, like a gourd that is grown into a mould […]”.

antupis• 4 years ago

I think it is fine as long as it works same way as grammarly. You don’t want lose customer becouse you sounded like ass on email. Otherhand running this kinda solution at corporate slack or all outbounding messages mass censorship way sounds horrible.

marcyb5st• 4 years ago

Mandatory link to real life story of something similar: https://www.reddit.com/r/LateStageCapitalism/comments/tev0ln...

Cthulhu_4• 4 years ago

I mean a lot of people aren't even aware they are, for example, being condescending - very common in e.g. HN comment threads. I'm sure this comment could be construed as condescending as well for that matter.

LightG• 4 years ago

I'm not a fan in the same way as I'm not a fan of Grammarly. I just don't like things intefering with my flow.

However, you have to hand it to Incluse.ly. it sounds like the perfect dynamic to trigger all manner of macroaggressive neurons in the anti-woke .... 'bEcAuSeeee the wOke sCarEy mEEEEE!!!!!!"

Hmmm, I need to tone down my microagressions. My apologies to all concerned.

noisy_boy2• 4 years ago

Nona Desalination says it has developed a device capable of producing enough drinking water for 10 people at half the cost and with 1/10th the power of other water desalination devices.

Not sure if it is a coincidence or not but "Nona" means salty in Bengali[0].

[0] https://en.wikipedia.org/wiki/Bengali_language

danbruc2• 4 years ago

Probably a coincidence, somewhere I saw the device name stylized as »no Na+«.

metaphor• 4 years ago

The winning team's research was previously discussed[1] a few weeks ago.

[1] https://news.ycombinator.com/item?id=31200793

turtledove2• 4 years ago

All of our fresh water comes from evaporation and precipitation. I'm curious if there have been attempts to increase evaporation as a means of producing water in areas with excess solar energy.

I know industrial plants use reverse osmosis, but is there somewhere experimenting with creating structures to encourage evaporation and then capturing the water vapor at scale? (Passively, I mean. I know we can just boil water at scale with expensive industrial systems.)

adrianN2• 4 years ago

Planting lots of trees is a moderately successful way of combating desertification.

Cthulhu_4• 4 years ago

I know sea salt is produced by filling up big pools and letting the sun do its thing, but capturing the water is challenging.

Although come to think of it, existing greenhouse technology would work, "just" fill a greenhouse with a layer of water or let it mist, then capture the precipitation off the roof. I'm pretty sure it needs a way to passively cool the thing though. I'm also sure there's a lot of factors why this wouldn't work, probably due to scalability compared to alternatives like reverse osmosis, land use, etc.

cestith2• 4 years ago

Solar stills work by putting something that can be as simple as a sheet of clear plastic over a hole in the ground, and putting a bowl under the peak of the sheet. A greenhouse with a brackish pool and a way to collect the precipitation would be a scaled up version.

https://www.sciencedirect.com/topics/engineering/solar-still

https://duckduckgo.com/?q=solar+still&iax=images&ia=images

rcMgD2BwE72F• 4 years ago

I'm curious if there have been attempts to increase evaporation as a means of producing water in areas with excess solar energy.

I guess we'd yield far better results in the long term by investing to lower greenhouse gas emissions anywhere in the world. We're still building coal plants in 2022!

dullynotsonumb• 4 years ago

First place project is great! But can't help myself and not compare the second place with other projects that are mentioned and feel speachless..

Hithredin• 4 years ago

Yeah... Such a great idea to have every company discussion validated and approved by an AI.

LoveMortuus• 4 years ago

In the whole article there isn't a single photo of the device...

westcort• 4 years ago

Key takeaways:

* Nona uses a technology developed in MIT’s Research Laboratory of Electronics that removes salt and bacteria from seawater using an electrical current

* “Because we can do all this at super low pressure, we don’t need the high-pressure pump [used in reverse osmosis], so we don’t need a lot of electricity,” says Crawford, who co-founded the company with MIT Research Scientist Junghyo Yoon

* The company has already developed a small prototype that produces clean drinking water

* The audience choice award went to Sparkle, which has developed a molecular dye technology that can illuminate tumors, making them easier to remove during surgery

* The MIT $100K is MIT’s largest entrepreneurship competition

* “Our device runs on less power than a cell phone charger.” The founders cited problems like tropical storms, drought, and infrastructure crises like the one in Flint, Michigan, to underscore that clean water access is not just a problem in developing countries

* The technology could also possibly be used for hydrogen production, oil and gas separation, and more

* “Our mission is to make portable desalination sustainable and easy,” said Nona CEO and MIT MBA candidate Bruce Crawford in the winning pitch, delivered to an audience in the Kresge Auditorium and online

If you want to see the others, please go here: https://www.mit100k.org/launch

Solar-powered desalination device wins MIT $100K competition

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