Engineers at MIT and in China are aiming to turn seawater into drinking water with a completely passive device that is inspired by the ocean, and powered by the sun.
In a paper appearing today in the journal Joule, the team outlines the design for a new solar desalination system that takes in saltwater and heats it with natural sunlight.
The researchers estimate that if the system is scaled up to the size of a small suitcase, it could produce about 4 to 6 liters of drinking water per hour and last several years before requiring replacement parts. At this scale and performance, the system could produce drinking water at a rate and price that is cheaper than tap water.
Article doesn’t mention what the unit does with the salt waste.
I support this 100%, but desalination presents a unique problem: what do we do with all the salt? Maybe the unit uses it for something, but otherwise it just miniaturizes a problem that we’re already working on.
If this works, it’s better than anything we have , which costs grid energy and dumps brine all the same. If anything, the smaller scale makes it easier to distribute and dilute the output brine.
If sea levels rise as much as they’re supposed to, this will be an invaluable tool for an enormous proportion of the country. My concern comes from capitalism getting its hooks into this.
Which country are you referring to?
Capitalism bad, sure, but you can’t deny it has a way of making things scalable and affordable. If some venture co started the infrastructure to mass produce this stuff and make it possible for everybody to afford it would it be that bad?
What? No, my friend you misunderstand. Mass-production makes stuff affordable and scalable. Capitalism makes it so wealth is horded and only the rich get to decide what gets made. You vote with your dollar while a billionaire votes with theirs, guess who wins.
Mass-production is not a capitalism-exclusive unlock, it’s a dlc that can be redeemed in any economic system.
Without the motivation to make a profit, few entities are both willing and able to engage in the considerable expense, risk, and effort required to spin up a mass production line.
I think “thirst” and “hunger” predate “profit” as a motive by several hundred million years.
Yeah, Neanderthals were famous for their efficient large-scale manufacturing capabilities
What a fantastic point. You can’t get a lion to chase a gazelle without a credit card these days.
Weird, there was lots of mass production in the Soviet Union. Please explain.
Governments are one of the few entities that are able (and occasionally willing) to spin up a mass production endeavor without the profit motive necessarily present.
Sometimes they essentially do this themselves via federal employees, or contractors. Sometimes they achieve the ends indirectly by incentivizing private companies with subsidies and the like.
Regardless of how it gets done, everyone shows up for work in the morning motivated by something. In the Soviet Union this was often the fear of imprisonment or other such violence, which was a really shitty situation for a lot of people to be in. In the modern world, it’s typically the hope that the money made will pay for food and housing and such.
when, all of human history must be like 250 years old…
Right. We live in a capitalistic society though, not in another one. So either “capitalism gets its hooks” on this stuff or it stays inconvenient and unaffordable. Then we can speak about fantasy scenarios all we want…
Don’t you just dump it back in the sea? Diluting should make this a minor issue right?
That’s what I always thought, but the local effects of hypersalinated water can be terrible for any nearby life
While true, I consider the issue very minor compared to getting people clean drinking water. There are no perfect solutions in society. Just a series of trade-offs, maximising benefits and minimising costs.
Yeah, that coastal community probably didn’t need any fish.
Large coastal communities don’t just go down to the local jetty and cast hooks into the water by the shore. Commercial fishing is done by large ships out in the ocean, far away from the cities.
You probably wouldn’t want to fish near a city’s sewer outflows anyway.
i consider 🤣 ehm ehm … I consider! I CONSIDER 😁
who the hell cares about what i consider? upvote this if you don’t give a shit about my considerations 😉
Thats the big ecological question. If we do this at scale, we’ll be releasing more briny water back into the sea than we take. Over time on industrial scales, what will this do to the oceans? Is the increased salinity negligible, even at large scales? Or will it cause marine wildlife to die out?
Think of it this way. Burning a pile of wood generates CO2. So first burning a bunch of gas or coal. A couple campfires won’t make a dent on the atmospheric composition. It’s only when we go this en masse and at industrial scales that we add appreciable CO2 to the atmosphere and cause global warming.
The ideal way to handle desalination would be for us to use the salt that’s produced, so the concentration in the ocean remains unchanged with respect to desalination.
But the water is all being returned to the ocean rather quickly. It’s not quite the same with CO2.
There’s some localized issues to deal with, but it’s not going to be a global salinity increase as we aren’t changing the form of the water and storing it, like the polar ice does.
So in fact, the ocean should already be desalinating slightly from the melting ice caps.
I thought about the ice caps, yeah. It’s just something that warrants long term monitoring and observation.
You cook with it.
Fellow Frenchman detected.
It’s able to successfully reject the salt waste, which is a success. The question will be if it can reject enough of it.
The brine itself though is a really good question. I think there’s some existing uses for it, but we’d probably need to think of new applications for it as well.
Just toss it back out in the ocean or make lots of jerky.
Salt is an essential nutrient. We already make it from seawater just to get the salt! Now we’ll get some clean water as well.
You put it back in the ocean. Laughable to think you would alter the ocean’s salt content this way. All of the freshwater produced would eventually end up back in the ocean anyway.
On the large scale this is true, but the problem is that the concentrated brine doesn’t instantly dilute back into the entire ocean. In large quantities, the waste outflow would damage the local coastal ecosystem before it was sufficiently diluted.
What is “sufficiently diluted” this device discharges brine at only slightly higher levels than what it takes in.
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They’re getting really good at working with tidal flow and weather to ensure they don’t cause problems, it’s just all got to be built into the system when they design it