Solar-powered desalination device wins MIT $100K competition
news.mit.edu
news.mit.edu
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?
> 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.
Like the ones NASA has on the shuttle https://www.nasa.gov/feature/new-brine-processor-increases-w... right?
> "The researchers also created a smartphone app that can control the unit wirelessly and report real-time data on power consumption and water salinity."
* 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
Huge props to MIT and the research team for this.
Not sure if it is a coincidence or not but "Nona" means salty in Bengali[0].
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.
Expecting Cunningham’s Law to show I goofed the math.
Average household water use in 100-200 liters per day.
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.
I think it’s very promising/exciting as a method of smoothing out the demand curves of the electric grid. Plus, it’s fairly straightforward to modify existing dams/hydro infrastructure to have this capacity.
Since some dams are already used as water reservoirs for drinking/agriculture, this could be quite viable if the desalination can be done cheaply and efficiently at scale (not sure if this is even possible on the scales required for this idea to make sense, though).
Perhaps one way of encouraging a "greener" grid is to first encourage the development of cheap energy storage solutions, and then letting the market figure out the best way to utilize such storage (rather than the other way around). Might lead to more efficient/creative green energy solutions.
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.)
Faucets will never go dry because human drinking water is a minuscule use. Some sprinklers and pools may go dry in times of drought
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.
I’d imagine a plant would benefit from economies of scale. Though these benefits could get eaten up by cost overruns. Frankly, it seems the hurdle in California is working through the people issues/concerns than technical problems.
It’ll be interesting to see the stats on this new desal technique when they have a product for sale.
https://www.reuters.com/world/us/california-staff-report-rec...
Across the US, farmers are not poor. By dint of being landowners, they are in fact some of the richest people around. See, e.g., this article: https://www.theatlantic.com/ideas/archive/2021/09/trump-amer... or this one: https://www.nytimes.com/2022/05/14/opinion/sunday/rich-happi....
This does not even make sence - Are they going to sell their farmland? To whom, other farmers? Are those other farnera not going to farm the famrland?
Back of the envelope math suggests that based on average rainfall amounts per year a place like Ventura county could be entirely self-sufficient without any desalination plants.
Agriculture can also switch to drip feeding water instead of spraying which cuts usage by 90% without lowering yields.
There's a lot that can be done. We just need the political will to make it happen.
Having extra reservoirs can also support more natural vegetation and potentially actually create conditions for more rainfall further from the coast.
Nice username :)
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.
Water that naturally flows into the state’s “wild and scenic” rivers, which are not connected to the state’s water system and can’t be under state and federal protections
Water required for maintaining fish and wildlife habitat within streams
Water that supports wetlands within wildlife preserves
Water needed to maintain water quality for agricultural and urban use
I'm unable to tell whether that's a tally for untapped water or if it's really meant to account for something meaningful.
The CFB does say that ag accounts for 80% of "human use".
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...
This is cathartic and fun to read - and it equally applies to bankers, and other highly paid wankers.
Our economy as a whole underpays and inderinvests in the foundamental things that allow advanced society to exist - as the whole climate crisis demobstrates.
Kek, as a former cook I should have structured those 2 metaphors differently, but yeah... ok yeah you got me on the play on words. Well played.
You wouldn't even need enclosed evaporation containers; let the wind carry the moisture to the mountains, raining into existing reservoirs.
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.)
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.
https://www.sciencedirect.com/topics/engineering/solar-still
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!
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.
> 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!
- 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.
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....
(1) https://news.ycombinator.com/item?id=31200793, also linked in the article for this post.
But that's what most hackathons are in reality anyways.
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”
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...
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.
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)
https://www.nauticexpo.com/prod/schenker/product-23417-55567...
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.
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.
- "This energy storage is only 30% efficient".
- "Yes but it's dirt cheap and so is solar peak power."
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.
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?
>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.
"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 […]”.
This is the kind of stuff that will cause good prospects to avoid ever applying to your company. Nobody wants to be second-guessed by a robot overlord (proof: Clippy).
People in the Rust community love clippy.
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.
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.
> 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).