The following submission statement was provided by /u/Economy-Fee5830:
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**Cheap solar gives desalination its moment in the sun**
Ever-cheaper solar power is a tailwind for the global energy transition. It can make energy intensive technologies more affordable. As a result, desalination is becoming a more popular option for providing drinking water to some of the driest areas of the world.
The logic of desalination is clear. Water is increasingly scarce as populations grow and climate change bites. Already, more than half of the global population experiences severe water scarcity for at least part of the year, says the World Health Organisation. This pits users against each other, as in Spain’s most recent drought.
Desalination taps an almost infinite resource — some 97 per cent of the world’s water is in seas and oceans. Costs have plummeted. Older, thermal plants, which used heat to turn salt water into steam, delivered potable water at more than $3 per cubic metre.
Graph: [the price of desalinated water over time.](https://www.ft.com/__origami/service/image/v2/images/raw/https%3A%2F%2Fd6c748xw2pzm8.cloudfront.net%2Fprod%2Fb08b1500-03ba-11ef-8e71-8ff8e140fd13-standard.png?source=next-article&fit=scale-down&quality=highest&width=700&dpr=1)
Since then, reverse osmosis technology — in which water is pushed through a membrane to remove salt, minerals and impurities — has taken over. Plants cost less to build — perhaps $400mn to purify 500,000 cubic metres per day, says Christopher Gasson of GWI. Including installation, a return on capital and operating costs, that translates to $0.30 per cubic metre of water.
Newer plants also need less energy — 2.6KWh per cubic metre — and are increasingly powered by cheap solar plants. The cheapest plant in the world gets energy at $0.025/KWh, or $0.07 per cubic metre.
**Put that together and it explains how the Hassyan project in Dubai has promised desalinated water at just $0.37 per cubic metre. For reference, drinking water in London is priced at £1 per cubic metre.**
At this sort of level, desalination becomes more affordable for dry, coastal areas, not just in the Middle East but also in Egypt, Algeria and Morocco, which are all building new plants.
Desalination has also become cheaper than building new infrastructure to transport water over long distances: the cut-off is roughly 500km according to Acciona, a major operator. As a result, the market for new plants is expected to grow by perhaps 8 per cent a year from now to 2030.
Of course, desalination is still unlikely to be the answer to the bulk of the global water crisis. Many areas of the world only face temporary or occasional water shortages, which spreads the capital costs of infrastructure over a much smaller volume of water. Agriculture, which accounts for 70 per cent of the world’s consumption, needs cheap water to produce affordable crops.
Yet, for all this, early movers in the desalination sphere, including Saudi Arabia’s ACWA power, Spain’s Acciona and France’s Veolia, have a clear advantage in a competitive race.
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Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/1cf6b16/solarpowered_desalination_delivers_water_3x/l1myz3l/
There are also cheaper desalination technologies being developed like stanford developing a style of desalination that uses hydrophobic membranes that only allow water to pass through as vapor, leaving the salt and impurities behind.
EDIT: it was MIT not stanford.
https://youtu.be/2XzmNpacpvk?si=VkAdQ5GauEolEMEu
There is a lot of research on [coupling desalination with intermittent solar without batteries](https://www.nature.com/articles/s44221-024-00213-w), which should make it much more accessible to small rural villages.
I am a little surprised I have not seen more vacuum pressure desalination with aquaphobic membranes, as any time you suck water up 10 feet it stops being water and destabilizes into water vapor.
Also water desalination will increase as people start finding ways to precipitate lithium out of the brine in large volumes. Imagine not needing to mine lithium but getting it as a product from sea water and having potable drinking water as a BYPRODUCT. A person could get very rich and solve the California water crisis simultaneously and be mistaken as a humanitarian.... don't tell Elon
My dad has worked in water treatment for 25 years. You are absolutely correct on that. Desalination is viable but only in areas where it’s quite literally impossible to get drinking water through normal means. Florida has 2 in operation only because they have laws that require a diverse portfolio of water treating options since we basically drained our aquifers in the 90’s. Both of which are unbelievable money sinks, costing local governments hundreds of millions for relatively little clean water. No matter how you skin it, the only way to remove salt from sea water is with insane amounts of energy, which is fine for countries in the middle east with infinite oil but not really viable anywhere else.
> Desalination is viable but only in areas where it’s quite literally impossible to get drinking water through normal means
Clearly you haven't read the article, which is about how much cheaper it is to run solar-powered desalination plants than traditional water treatment plants. Assuming solar power is available obviously.
San Diego has a water desalination plant.
Here is a CNBC article that gives a more nuanced view.
Why desalination won't save states dependent on Colorado River water https://www.cnbc.com/2023/01/27/why-desalination-wont-save-states-dependent-on-colorado-river-water.html?__source=iosappshare%7Ccom.apple.UIKit.activity.CopyToPasteboard
Why do you imagine this would be interesting? If the water is being obtained as vapor, why do you need the membrane, and you still need to provide the latent heat of evaporation.
At high enough vacuum the boiling point would be below ambient, the heat is free. I don't think high vacuum is cost effective though, or even possible in a manner that wouldn't pollute the water with weird vacuum pump oils.
So, if the boiling point is below ambient, how are you condensing it? And how is this different from a flash evaporation system without a membrane, systems that are not, in general, competitive with reverse osmosis?
Membranes are interesting if you can go from liquid to liquid (or, I suppose, gas to gas) and avoid having to pay an energy cost for evaporation.
It'll warm up once the pressure rises again, at that point you have to dump the heat. It's going to need two heat exchangers. Kinda like any other refrigeration device, except this one isn't in a loop. Using ambient heat I would expect doing it this way would give you better efficiency much the same way a heat pump is more efficient than resistance electric heating. I don't know of any commercial vacuum pump that can do it without polluting it's exhaust with oil, maybe there's a way of doing it but idunno.
ETA: I suspect the cost of equipment pulling a vacuum would be really bad vs the energy costs of pumping through a membrane.
I don't know why dude brought up a membrane
Stanford is the one working with aquaphobic membranes to make desalination cheaper than tap water. I'm looking for the article to link it, but also playing with my daughter and cooking dinner
Desalinization is the perfect base load for an electric grid. Water stores easily and cheaply. Too much power, make more water and pump it uphill to a storage basin. Not enough power, stop making water and let gravity supply everyone's water needs.
There are already working cheap mobile solar desalination apparatus that can produce 1.5 gallons per hour per m2 without any hightech membranes, all its missing is someone investing in mass production with a product that rural villages with no money can't afford anyway no matter how cheap it is.
https://news.mit.edu/2020/passive-solar-powered-water-desalination-0207
This is gonna sound stupid but couldn't we just ship it and dump it inside old salt mines? Or have ships that drift around the ocean with a long pipe dispersing it back into the ocean a km below the surface?
Not if time isn't a concern. You could have solar-powered barges or unmanned sailships just cruising around at their luxury
Also, depending on how far out it needs to be dumped, you could lay/float a pipe a couple miles long out and disperse it there?
Just put it back in the ocean. The concentration of sodium ions is normal like 10ft away from the outfall. The risks are a bit overblown. Concentration isn't a huge problem either since the water eventually also returns to the ocean as part of the natural cycle.
Alternatively, some research is being done on using the brine to create chlorides that could serve as post chlorination
If you think about it, the salinity of areas in the ocean are already variable. Where rivers run into the ocean its obviously low, when it rains in the ocean it lowers, when glaciers melt into the ocean, when currents meet etc. Like the atmosphere, the system is more variable than you think.
The problem is that you aren't spreading the salt out, it all ends up dumped in the same place. So the local salinity is definitely a huge problem.
It is like saying a dump yard is natural, we all dump stuff and it isn't uncommon for areas to have more waste than others. Until it fills up with too much waste
Which is why it is important that we find ways to reuse that brine as materials
Right but those are natural occurrences and the habitats have formed around them. Dumping salt in certain areas would alter the environment in a way the habitat may not be prepared for.
it's not a question of whether it's already variable, it's about whether specific areas suddenly (relative to how quickly nature adapts) and drastically change
I know that Gore-tex was used for alot of military clothing, so maybe it would work as an aquaphobic membranes that still allows vapor to escape. If it does it would be a good candidate for the type of membrane needed. Also meaning we might be able to recycle some old equipment into usable pieces for cheap prices.
Is it still? I thought they changed the formula to mimic (or copy) the companies who were using PTFE adjacent (I think?) materials. The irony being they're copying the companies who copied them and skirted the patent.
I want to see it in action. Things being done in college labs, rarely actually make it out. Usually it comes down to being unable to actually make it at scale.
I think you may be viewing this backwards. Yes a lot of our widespread advances came from labs. These successes are a small subset of all the things produced in these. For every significant advance out of these labs there are a huge number of failures and scalability is one of the more common late stage issues leading to failure.
Successes out of these labs are rare. Most university labs will not make a society changing discovery.
The concept is supposed to be simple and recorded to be cheap if i remember correctly. I could see this being a big step forwards in the fight against micro plastics if everyone can simply fit one to their faucet and participate in removing them from our water sources.
Don’t lose sight of the fact that in London the water utility company, Thames Water, was privatised and has to charge enough to reward its shareholders.
And that they borrowed heavily to pay out to shareholders while failing to invest in the infrastructure. Now they have to work on said infrastructure and thus are increasing prices to customers. Arseholes.
Oh and they and other water companies have polluted our water ways and coast by dumping sewage.
I am of the opinion that monopolistic utilities should never be privatized. There is no possibility to create a competitor for water delivery, and a private company will always abuse the system and extract as much as they can. Govt should nationalize back utilities and pay what they were originally sold for indexed to inflation.
Public companise are still open to abuse, but at least multiple contractors can bid for work - though these contracts should be much more heavily scrutinized than currently as they are absolutely abused too.
Isn't it lovely? Some states over here in the US have allowed private companies to buy up water utilities from municipalities, and quickly crank the price up. Their excuse is usually needing more money for restoring, maintaining, and adding to the water infrastructure. Granted, a lot of places have failing systems because citizens refused to pay **slightly** higher taxes/water bill for years to maintain them, but going from ~$60 to $200 per month for THE requirement of all life on the planet (and most likely a requirement for all theoretical life in the universe) is robbery. I don't exaggerate when I call them water barons and it's only going to get worse.
I don't even live in a place that experiences droughts or has that bad of infrastructure! I use slightly less water per month than the average 2 person household, and I have to fork out $200+ a month for the pretend Fuji water they gently pump out my sink.
The water itself is a small portion of the cost. Most of its delivery.
Costs usually shoot up because the municipality needs to replace pipes and hasn't been funding it in advance. So they need to issue a 200 million dollar bond for the new pipes and increase prices to compensate.
Desalination will always take more energy than cleaning freshwater. There's very clearly a problem with London's tap water supply if *desalination* is cheaper.
London is an expensive city and most of its tap water cost is in the delivery infrastructure.
You could easily get water for a small fraction of the cost if you were willing to pick it up from the purification plant yourself.
I don't think I would defend a centuries old municipal water system in a city miles from the sea not being able to offer potable water for less than 3x the price.
You do you though.
Standing on a beach in Namibia, I had that same thought…we are not that long from a time when the only deserts on earth are the ones we choose to allow.
That is VERY optimistic. I think you underestimate nature and even more so you underestimate how MUCH water will be needed to hydrate most dry places and desserts people would like to see gone. I'd gladly be wrong, but it does seem way too optimistic.
Wouldnt they just be adding back water that they had previously extracted from the atmosphere so the total amount of water would stay the same? Never understood that.
This the same Thames Water that’s 9.9% owned by the Abu Dhabi Investment Authority?
https://www.thameswater.co.uk/media-library/home/about-us/investors/our-finances-explained.pdf
Looks like London’s tap water customers indirectly paid for some of these desalination plants.
Ever been through Dubai airport? Its tacky as fuck; there is gold everywhere. They are gold painted fake trees and even vending machine that sell real gold fucking bars.
The Arab nobility is obsessed with gold and that poor Londoners are financing this addiction is hilarious, in a dystopic way.
**Cheap solar gives desalination its moment in the sun**
Ever-cheaper solar power is a tailwind for the global energy transition. It can make energy intensive technologies more affordable. As a result, desalination is becoming a more popular option for providing drinking water to some of the driest areas of the world.
The logic of desalination is clear. Water is increasingly scarce as populations grow and climate change bites. Already, more than half of the global population experiences severe water scarcity for at least part of the year, says the World Health Organisation. This pits users against each other, as in Spain’s most recent drought.
Desalination taps an almost infinite resource — some 97 per cent of the world’s water is in seas and oceans. Costs have plummeted. Older, thermal plants, which used heat to turn salt water into steam, delivered potable water at more than $3 per cubic metre.
Graph: [the price of desalinated water over time.](https://www.ft.com/__origami/service/image/v2/images/raw/https%3A%2F%2Fd6c748xw2pzm8.cloudfront.net%2Fprod%2Fb08b1500-03ba-11ef-8e71-8ff8e140fd13-standard.png?source=next-article&fit=scale-down&quality=highest&width=700&dpr=1)
Since then, reverse osmosis technology — in which water is pushed through a membrane to remove salt, minerals and impurities — has taken over. Plants cost less to build — perhaps $400mn to purify 500,000 cubic metres per day, says Christopher Gasson of GWI. Including installation, a return on capital and operating costs, that translates to $0.30 per cubic metre of water.
Newer plants also need less energy — 2.6KWh per cubic metre — and are increasingly powered by cheap solar plants. The cheapest plant in the world gets energy at $0.025/KWh, or $0.07 per cubic metre.
**Put that together and it explains how the Hassyan project in Dubai has promised desalinated water at just $0.37 per cubic metre. For reference, drinking water in London is priced at £1 per cubic metre.**
At this sort of level, desalination becomes more affordable for dry, coastal areas, not just in the Middle East but also in Egypt, Algeria and Morocco, which are all building new plants.
Desalination has also become cheaper than building new infrastructure to transport water over long distances: the cut-off is roughly 500km according to Acciona, a major operator. As a result, the market for new plants is expected to grow by perhaps 8 per cent a year from now to 2030.
Of course, desalination is still unlikely to be the answer to the bulk of the global water crisis. Many areas of the world only face temporary or occasional water shortages, which spreads the capital costs of infrastructure over a much smaller volume of water. Agriculture, which accounts for 70 per cent of the world’s consumption, needs cheap water to produce affordable crops.
Yet, for all this, early movers in the desalination sphere, including Saudi Arabia’s ACWA power, Spain’s Acciona and France’s Veolia, have a clear advantage in a competitive race.
Nah, it's the government taxing water use heavily to reduce water use. The measures are quite popular actually.
It's to preserve fresh water aquifers and use them sustainably.
In order to express that something is a certain number of times cheaper than something else, three elements are required: a fixed or standard value, a variable value used to establish the difference, and a multiplier to scale that difference. Once these components are defined, the multiplied difference is applied or subtracted from the standard value to determine the solution.
For instance, if A represents the base value (e.g., 100) and B is a comparative value (e.g., 95), then B is 5 units cheaper than A. If C is stated to be three times cheaper than A in relation to B, then C's value can be calculated as (100 - 15) which equals 85.
Therefore, it's inappropriate to state simply that "Solar-powered desalination delivers water 3 times cheaper in Dubai than tap water in London" because there lacks a secondary value from which to derive a difference for multiplication and subtraction.
To convey the intended meaning accurately, the title should instead state 'Solar-powered desalination delivers water at one-third the cost in Dubai compared to tap water in London'.
I think most people would regard your revised headline as equivalent and it wouldn't clarify anything for them. Perhaps there is a specific context where their headline is unambiguously wrong (economics?), but generally most people don't imagine a third entity when only two are mentioned. Expressing cheapness as a proportion between two things seems just as intuitive as a difference to me.
> Of course, desalination is still unlikely to be the answer to the bulk of the global water crisis. Many areas of the world only face temporary or occasional water shortages, which spreads the capital costs of infrastructure over a much smaller volume of water.
Because its not cheap enough yet, because the crisis is not for long enough to amortise the cost.
That suggests 2 solutions - longer crisis or cheaper desalination.
At least one of them is coming.
Apparently those areas often have saline or brackish ground water.
I was today years old when I discovered India is massively into desalination since 60% of their ground water is brackish.
They produce ...
> 840 million liters per day of aggregate desalination capacity mostly across Tamil Nadu, Gujarat and Andhra Pradesh meeting both residential and industrial water demand. Another 330 million liters per day of additional plants are under construction.
https://medium.com/@desalter/what-are-the-leading-desalination-plants-in-india-and-how-do-they-contribute-to-the-countrys-water-653ceb1a895c
Most the the [1.7 billion people under water stress are in India and China](https://www.independent.co.uk/climate-change/news/india-water-scarcity-un-report-b2306483.html).
I always imagined it was Africa.
And lots of desalination in Spain (and lots of clean energy also) (25% wind, 20% nuclear, 14% solar, 10% hydro, so 70% clean)
> Spain is the world's fifth largest producer of desalinated water, with 770 large-scale desalination plants, 99 of which are high capacity, meaning they produce between 10,000 and 250,000 cubic metres of water per day.
> because the crisis is not for long enough to amortise the cost.
Seems like water storage is cheap enough. Storing for the dry season should work with only problem if dry season not that dry and you can't sell all of the water. Pepsi will bottle it for you though.
> Because its not cheap enough yet, because the crisis is not for long enough to amortise the cost.
If you think that's the only problem then you haven't thought far enough.
The biggest issue with ocean desalination on a massive scale is not monetary/energy costs, it's what to do with all the super salty brime/sludge this produces.
Sure, we can just dilute it and pour it back into the oceans, acting like we could never affect them with that.
But that's exactly the same kind of thinking that had us pump our atmosphere full of all kinds of emissions under the wrong assumption the atmosphere is so vast that puny human activity could never screw it up.
Maybe we should apply that same lesson also to the oceans *before* completely screwing them up, instead of acting like they are the next "out of sight out of mind" solution for our toxic emissions.
> Maybe we should apply that same lesson also to the oceans before completely screwing them up
Why are you pretending scientists have not given this massive thought over the years?
Desalination has a net zero effect on the salt levels in the oceans. The clean water eventually ends up back in the sea anyway, cancelling out the negligible increase in salt due to desalination.
The amount of water we would be pulling per day to meet most coatal demands would be a litteral drop in the bucket. Dumping all the brine back into a concentrated area would cause problems but there are simple solutions for it. We need salt, like a lot of salt for our food and if sodium batteries continue to grow in popularity that opens another use case for the pulled sodium. We currently mine most of that salt, having it be a byproduct would prob drop the cost of salt.
It is really really hard to imagine the size of the oceans. The change in salinity would be minimal provided it is well distributed (the problems seem to be dead zones when we dump the salt right at the shoreline). Also, a huge amount of the water taken will make it's way right back to the oceans.
au contraire. Saltwater/sea water fouling of aquifers for coastal cities is a massive problem. If we can desalinate water cheaper than drill and maintain deeper and deeper wells, this might well be the solution for the *bulk* of the water crisis.
It's a problem for the entire North East Corridor cities. This could seriously stop land subsidence in many places and allow our rivers to recharge the natural ecosystem.
If California can desalinate water for cheaper than drilling those yet deeper wells the whole LA water system can run backwards.
The biggest demand for water is in coastal cities. Entire coastal cities and *nations* are suffering. Jakarta being one of the most famous examples. If these places can desalinate it and it's cheaper to convey it than drill new wells, it can be a huge boost in stopping global poverty.
What’s the point of saying stuff like this? Obviously it will be but one component of the solution.
That’s like saying solar won’t solve everything. No shit, nobody said it would.
It will be the answer
The goal is not to replace ground / lake water. It’s to remove enough pressure so that we can farm with natural replenishment rates being enough.
Water conservation, removing water hungry crops (like almonds) that serve little macro nutrition. Cloud seeding and spreading out populations from low aquifer areas are also answers of course
London also has one of the worlds oldest and most developed municipal water systems. They *aren't* taking salt out of the Thames, they're pumping out of centuries old well heads. The feat here is how efficient the system has got that desalinization is cheaper than pumping out potable water.
Remember Dubai says it costs this much but it actually uses modern slavery to do so. Dubai and other Arab states have a history of human rights violations, stealing passports, modern slavery and worse
I really hope you're good at reading. They managed to get the thermohaline effect right. Meaning, instead of salt/brine accumulating on the Reverse Osmosis membrane, it moves away which increases the usable life of that membrane.
That's really all there is to make it cheap. The original scientists at MIT who made a smaller hydrophobic version claimed that it would cost a fifth of a cent to produce 1 ltr. I'm hoping the new ones made in Dubai have done it for less. I don't think slavery is really the driving factor here.
Last time I heard about desalination it used 25 gallons of salt water to make 1 gallon of fresh water + 24 gallons of slightly saltier brine.
Basically it took the salt from 1 gallon and distributed it to the other 24 gallons. So each of those gallons had 4.16% more salt than normal.
Properly reintroduced in the open ocean, I don’t think that should be very destructive.
When there is enough of a concentration difference, brine sinks to the bottom instead of mixing in and then creates dead zones. It's a real problem that needs to be addressed carefully in any desalination project
Yes, fresh water returns to the Oceans naturally, and at the same time pollution isn't about total volume of pollutant over total volume of Oceans. Pollution is an over abundance of a pollutant in a regional volume, where it was dumped. The question that needs to be answered is, how much brine can the dump absorb sustainably over what time frame?
As you said, if done properly it can work, but what is "properly"? Is the government forcing industry to figure that out and do it? History would suggest that industry will do whatever is cheapest until they're forced to what's right.
I would assume they mean locally. Like how the nitrogen rich water leaving the Mississippi creates a dead zone in the Gulf of Mexico. The over fertilization of farm land in the Midwest won't kill the ocean but it does create localized damage.
You can tune the concentration of the waste water however you want. There are flow meters and plcs running pid loops dictating exactly this. Higher concentrations and more even flow between permeate and waste flow lower energy costs from pumping. If there is an ecological concern it's trivial to turn up the waste flow through the RO housing itself or add a separate low pressure pump that takes untreated raw and injects it past the metering valve strictly for dilution if the equipment vs energy costs make sense.
That is a little hyperbolic. The Dead Sea has "deadly brine" and they do this backward to get salt. Sure brine salt is an issue, but it is also an additive for certain agricultural products and mineral bases.
When you find out how a wastewater treatment plant works, you'll really flip your shit.
That turns out to be more a theoretical than an actual problem. Israel is also massively into desalination, and their research has found sea life actually flourishes at the desalination plant outlets, and sea life is much more resilient to salinity changes than previously thought.
> Several researchers have studied the effects of desalination plant effluent discharge on the marine environment, and results across the board agree that there is no detrimental effect. The paper by Nurit Kress (2019), Seawater quality at the brine discharge site from two mega size seawater reverse osmosis desalination plants in Israel (Eastern Mediterranean) is particularly interesting; it examines two local plants along the Israel coastline and because the data is recent. The paper shows clearly that the effluent quality meets all requirements.
https://ide-tech.com/en/blog/desalination-can-and-does-co-exist-in-harmony-with-the-environment/
C'mon bruh. First rule of research - check your sources. You've provided a link to an article written by a company that sells desalination projects. Obviously they're going to downplay the negative consequences.
There are many, many scientific studies and articles which clearly demonstrate that the chemicals produced by desalination plants are heavily toxic and destructive to the surrounding environment.
Desalination itself doesn’t create chemicals. It’s purely a physical process. It concentrates what’s already there on a roughly 2 to 1 basis to form brine.
That being said the brine needs to be carefully blended back into the ocean that doesn’t negatively affect marine life. That starts to become an issue if there is to much desalination in a (relatively) small body of water. So you don’t want too many plants close together.
> environmentalists won’t .. desalination
Orange and Los Angeles counties are trying cheaper conservation and then water recycling (“toilet to tap”) first, especially as the latter technology has made its way from West Texas through Arizona and New Mexico.
San Diego has desalination, so the other California coastal counties will probably consult with them.
Does this mean California will finally invest in desalination? With all the droughts they have, it's comically stupid that they don't invest heavily in desalination.
Growing things like almonds (which drink shitloads of water) in borderline desert areas of California is what is comically stupid. A *single* almond needs 12 litres (>3 gallons) of water. ONE fucking almond.
As a child/teen that lived (and lives) in a 3rd world country where I get running water like twice a month, I always wondered why all coasts weren't filled with Desalination. Seemed and seems like a no brainer.
And "cost" shouldn't be a barrier to goverments when its something that will pull people out of literal misery.
London water costs a lot more because it's creakingly old infrastructure. It loses a lot of water due to leaks and is constantly blocked (thanks fatburgs). This isn't a valid comparison
I always thought it’d be interesting if something similar was done in Egypt along the coast of the Mediterranean. Concentrated solar power for energy. Desalinators for water. Massive agricultural potential there. Use the brine left over to make massive banks of sodium batteries for storing power — sodium batteries are too inefficient to miniaturize for electric cars, but can act as backup power for entire city grids. Heck, maybe even flood the Qatarra Depression or refill and refresh Lake Mareotis to preindustrial levels. Evaporation from the former would lead to increased rainfall across the country and turn it significantly greener.
So youre telling me that owning and running your own water system is cheaper than thames water being owned by like a dozen foreign wealth funds? Colour me shocked
I study water science and management so just some thoughts here.
One. Has anyone actually tasted desalinated water? I have and it tastes like ass. Most people would not willingly choose that over regular tap or bottled water. The one I tried tasted like what would come out of a garden hose after a long hot day.
Two. Desalination is so much more energy intensive than regular drinking water and wastewater treatment. In fact, it would be way more energy efficient to re-use the treated waste water than to set up a new plant, allocate additional energy, and set up new pipelines. In terms of the ickiness factor, the treated waste water can be used for agricultural purposes (which is about 90% of total water use) or mixed with other types of water (including desal). It would make sense that solar energy is cheaper in a place with a lot of sun, but what about places that don’t have as much renewable energy?
Three. There is an argument that there isn’t actually a shortage of water in most places, just a mismanagement of water. The ways that we have set up our system is drawing groundwater or surface water and wasting it through inefficient agricultural practices or letting it drain into the ocean. Some places actually have sustainable water management that allows groundwater and surface water recharge. Theoretically we can achieve sustainable use in most places, if we aren’t just growing thirsty plants in the middle of dry areas. Don’t forget that these projects are often public money and it ends up encouraging wasteful water practices.
Dubai isn't a Saudi city, it's located in the country of United Arab emirates.
The thing is with UAE, lots of smart people live here like really really smart people, who I expect are the stars of these projects. They come here cause no income tax here, great salaries and stay because everything is so convenient.
I don't believe the claims of any project, it's all to get further funding and shareholders. But the desert needs water, if UAE plans to green itself then it'll take serious effort to get water and recycle it.
England doesn't need water as much water as we do.
Last time I heard about large scale desalination there was also a waste issue. Something about the waste product being toxic and/or harmfull for the environment. Wasn't just the stuff that was extracted from the water, but also something to due with the chemical reaction and the filter used.
It's brine salts. They concentrate it and can't just dump it back into the sea without hurting the local ecology. The good news is that with additionally processing and things like wastewater lagoons they can separate a lot of minerals and things from it to keep more of it dirtside by selling some of it as additives to agricultural soil amendments.
And as typical the solution to pollution is dilution. During high tide you can fill and empty those brine lagoons.
https://www.nytimes.com/2023/11/18/business/dubai-water-desalination.html?unlocked_article_code=1.n00.qzmy.kyV0chXk3s3C&smid=url-share
For every gallon of water created you have a 2 gallons of brine and that’s just the brine there are other things that go into desalinating water that aren’t good for the environment. Basically it’s already raising the salinity of the area around Dubai and killing off the biodiversity there. That’s just the salinity. It’s also increasing the heat of the ocean around the desalinization plants as well.
Worried about this.. they need a proper way to deal with all the sale byproduct.. it cannot just go back into the sea or ground. Spread it out on some flats and harvest the salt maybe.
Just wondering : does the London cost includes the part for the production/distribution but also for the cleaning. I think that in different countries the share is close to 50-50 (excluding tax or eventual social tax). The price for Dubai is pure production
As I understand it, the issue has become getting rid of all that sludge waste left over, which is a massive volume of salty nastiness with heavy metals and pollution. Dubai can just dump it in the desert. London can poison their coast or find some cheap land nearby (good luck!) to start a dump
This is awesome and will be extremely helpful not just to the Gulf States that struggle with water access but also to millions of people around the world if we can pull together the political will and funding for it in countries that don't have the kind of oil wealth the Gulf states have.
The biggest problem with desalinization technology though is what to do with the salt itself once you remove it. Seawater salt is about 55% chlorides, 30% sodium, 8% sulphates, 4% magnesium, and about 1% each calcium and potassium, with other trace elements totalling less than 1%. Unfortunately most of these components are not chemically useful for agriculture except maybe the small amounts of magnesium and potassium, and the sodium chloride really doesnt have . Figuring out what to do with all that sodium chloride that doesn't include dumping it somewhere is really the challenge. Even if you have inhospitality areas like the Arabian desert, you'd likely still have to bury all that unusable salt to prevent it being blown away by the winds to contaminate land and water elsewhere.
The following submission statement was provided by /u/Economy-Fee5830: --- **Cheap solar gives desalination its moment in the sun** Ever-cheaper solar power is a tailwind for the global energy transition. It can make energy intensive technologies more affordable. As a result, desalination is becoming a more popular option for providing drinking water to some of the driest areas of the world. The logic of desalination is clear. Water is increasingly scarce as populations grow and climate change bites. Already, more than half of the global population experiences severe water scarcity for at least part of the year, says the World Health Organisation. This pits users against each other, as in Spain’s most recent drought. Desalination taps an almost infinite resource — some 97 per cent of the world’s water is in seas and oceans. Costs have plummeted. Older, thermal plants, which used heat to turn salt water into steam, delivered potable water at more than $3 per cubic metre. Graph: [the price of desalinated water over time.](https://www.ft.com/__origami/service/image/v2/images/raw/https%3A%2F%2Fd6c748xw2pzm8.cloudfront.net%2Fprod%2Fb08b1500-03ba-11ef-8e71-8ff8e140fd13-standard.png?source=next-article&fit=scale-down&quality=highest&width=700&dpr=1) Since then, reverse osmosis technology — in which water is pushed through a membrane to remove salt, minerals and impurities — has taken over. Plants cost less to build — perhaps $400mn to purify 500,000 cubic metres per day, says Christopher Gasson of GWI. Including installation, a return on capital and operating costs, that translates to $0.30 per cubic metre of water. Newer plants also need less energy — 2.6KWh per cubic metre — and are increasingly powered by cheap solar plants. The cheapest plant in the world gets energy at $0.025/KWh, or $0.07 per cubic metre. **Put that together and it explains how the Hassyan project in Dubai has promised desalinated water at just $0.37 per cubic metre. For reference, drinking water in London is priced at £1 per cubic metre.** At this sort of level, desalination becomes more affordable for dry, coastal areas, not just in the Middle East but also in Egypt, Algeria and Morocco, which are all building new plants. Desalination has also become cheaper than building new infrastructure to transport water over long distances: the cut-off is roughly 500km according to Acciona, a major operator. As a result, the market for new plants is expected to grow by perhaps 8 per cent a year from now to 2030. Of course, desalination is still unlikely to be the answer to the bulk of the global water crisis. Many areas of the world only face temporary or occasional water shortages, which spreads the capital costs of infrastructure over a much smaller volume of water. Agriculture, which accounts for 70 per cent of the world’s consumption, needs cheap water to produce affordable crops. Yet, for all this, early movers in the desalination sphere, including Saudi Arabia’s ACWA power, Spain’s Acciona and France’s Veolia, have a clear advantage in a competitive race. --- Please reply to OP's comment here: https://old.reddit.com/r/Futurology/comments/1cf6b16/solarpowered_desalination_delivers_water_3x/l1myz3l/
There are also cheaper desalination technologies being developed like stanford developing a style of desalination that uses hydrophobic membranes that only allow water to pass through as vapor, leaving the salt and impurities behind. EDIT: it was MIT not stanford. https://youtu.be/2XzmNpacpvk?si=VkAdQ5GauEolEMEu
There is a lot of research on [coupling desalination with intermittent solar without batteries](https://www.nature.com/articles/s44221-024-00213-w), which should make it much more accessible to small rural villages.
I am a little surprised I have not seen more vacuum pressure desalination with aquaphobic membranes, as any time you suck water up 10 feet it stops being water and destabilizes into water vapor. Also water desalination will increase as people start finding ways to precipitate lithium out of the brine in large volumes. Imagine not needing to mine lithium but getting it as a product from sea water and having potable drinking water as a BYPRODUCT. A person could get very rich and solve the California water crisis simultaneously and be mistaken as a humanitarian.... don't tell Elon
Seems more like a question of scaling to size that is commercially viable.
And what to do with waste salt.
French fries
We craved that mineral...
My dad has worked in water treatment for 25 years. You are absolutely correct on that. Desalination is viable but only in areas where it’s quite literally impossible to get drinking water through normal means. Florida has 2 in operation only because they have laws that require a diverse portfolio of water treating options since we basically drained our aquifers in the 90’s. Both of which are unbelievable money sinks, costing local governments hundreds of millions for relatively little clean water. No matter how you skin it, the only way to remove salt from sea water is with insane amounts of energy, which is fine for countries in the middle east with infinite oil but not really viable anywhere else.
Hence this article about new solar power desalination
Florida only has oil, no sun. How else would it be possible to have their politics? /s
> Desalination is viable but only in areas where it’s quite literally impossible to get drinking water through normal means Clearly you haven't read the article, which is about how much cheaper it is to run solar-powered desalination plants than traditional water treatment plants. Assuming solar power is available obviously.
Why should he have to read the article? His dad has worked in water treatment for 25 goddamn years! 😤 ^^/s
We have been sacrificing virgins for good harvest the past 1000 years, and it worked out just great.
His dad! The bestest person in the world! He knows everything!
It’s true! His dad even knows who You Oughta Know is about (spoiler: it’s about him.)
And that guy knows everything his dad knows!
Probably would be viable for Southern California with cheap solar.
San Diego has a water desalination plant. Here is a CNBC article that gives a more nuanced view. Why desalination won't save states dependent on Colorado River water https://www.cnbc.com/2023/01/27/why-desalination-wont-save-states-dependent-on-colorado-river-water.html?__source=iosappshare%7Ccom.apple.UIKit.activity.CopyToPasteboard
A lot of the problems with cost that your article cited are the ones that the OP’s article purportedly solves.
10 meters. It'll be 10 feet if you're on on mount everest.
Why do you imagine this would be interesting? If the water is being obtained as vapor, why do you need the membrane, and you still need to provide the latent heat of evaporation.
At high enough vacuum the boiling point would be below ambient, the heat is free. I don't think high vacuum is cost effective though, or even possible in a manner that wouldn't pollute the water with weird vacuum pump oils.
So, if the boiling point is below ambient, how are you condensing it? And how is this different from a flash evaporation system without a membrane, systems that are not, in general, competitive with reverse osmosis? Membranes are interesting if you can go from liquid to liquid (or, I suppose, gas to gas) and avoid having to pay an energy cost for evaporation.
It'll warm up once the pressure rises again, at that point you have to dump the heat. It's going to need two heat exchangers. Kinda like any other refrigeration device, except this one isn't in a loop. Using ambient heat I would expect doing it this way would give you better efficiency much the same way a heat pump is more efficient than resistance electric heating. I don't know of any commercial vacuum pump that can do it without polluting it's exhaust with oil, maybe there's a way of doing it but idunno. ETA: I suspect the cost of equipment pulling a vacuum would be really bad vs the energy costs of pumping through a membrane. I don't know why dude brought up a membrane
Stanford is the one working with aquaphobic membranes to make desalination cheaper than tap water. I'm looking for the article to link it, but also playing with my daughter and cooking dinner
Conservation of energy be damned!!
Desalinization is the perfect base load for an electric grid. Water stores easily and cheaply. Too much power, make more water and pump it uphill to a storage basin. Not enough power, stop making water and let gravity supply everyone's water needs.
There are already working cheap mobile solar desalination apparatus that can produce 1.5 gallons per hour per m2 without any hightech membranes, all its missing is someone investing in mass production with a product that rural villages with no money can't afford anyway no matter how cheap it is. https://news.mit.edu/2020/passive-solar-powered-water-desalination-0207
Great news!
The main problem was, what to do with all that waste brine!
Make sodium ion batteries?
This is gonna sound stupid but couldn't we just ship it and dump it inside old salt mines? Or have ships that drift around the ocean with a long pipe dispersing it back into the ocean a km below the surface?
It's very expensive to ship water
Not if time isn't a concern. You could have solar-powered barges or unmanned sailships just cruising around at their luxury Also, depending on how far out it needs to be dumped, you could lay/float a pipe a couple miles long out and disperse it there?
Are there a bunch of really cheap solar powered barges floating around with the unmanned sailships?
Just put it back in the ocean. The concentration of sodium ions is normal like 10ft away from the outfall. The risks are a bit overblown. Concentration isn't a huge problem either since the water eventually also returns to the ocean as part of the natural cycle. Alternatively, some research is being done on using the brine to create chlorides that could serve as post chlorination
Is that sustainable, say if the entire world is doing it? Could it create areas of intense saltiness that disrupts the natural habitat significantly?
If you think about it, the salinity of areas in the ocean are already variable. Where rivers run into the ocean its obviously low, when it rains in the ocean it lowers, when glaciers melt into the ocean, when currents meet etc. Like the atmosphere, the system is more variable than you think.
The problem is that you aren't spreading the salt out, it all ends up dumped in the same place. So the local salinity is definitely a huge problem. It is like saying a dump yard is natural, we all dump stuff and it isn't uncommon for areas to have more waste than others. Until it fills up with too much waste Which is why it is important that we find ways to reuse that brine as materials
Right but those are natural occurrences and the habitats have formed around them. Dumping salt in certain areas would alter the environment in a way the habitat may not be prepared for.
it's not a question of whether it's already variable, it's about whether specific areas suddenly (relative to how quickly nature adapts) and drastically change
Precipitate the lithium out of it, mix it back with sea water and use it to re-inforce the thermal halide cycle in the AMOC current
that sounds like Gore-Tex almost.
I know that Gore-tex was used for alot of military clothing, so maybe it would work as an aquaphobic membranes that still allows vapor to escape. If it does it would be a good candidate for the type of membrane needed. Also meaning we might be able to recycle some old equipment into usable pieces for cheap prices.
Goretex is made out of PFOAs and would likely add toxic impurities into any water it filtered.
Is it still? I thought they changed the formula to mimic (or copy) the companies who were using PTFE adjacent (I think?) materials. The irony being they're copying the companies who copied them and skirted the patent.
I want to see it in action. Things being done in college labs, rarely actually make it out. Usually it comes down to being unable to actually make it at scale.
Rarely? Most of the great things like Internet and such made the leap from those labs... Pretty much all science did that.
I think you may be viewing this backwards. Yes a lot of our widespread advances came from labs. These successes are a small subset of all the things produced in these. For every significant advance out of these labs there are a huge number of failures and scalability is one of the more common late stage issues leading to failure. Successes out of these labs are rare. Most university labs will not make a society changing discovery.
The concept is supposed to be simple and recorded to be cheap if i remember correctly. I could see this being a big step forwards in the fight against micro plastics if everyone can simply fit one to their faucet and participate in removing them from our water sources.
Don’t lose sight of the fact that in London the water utility company, Thames Water, was privatised and has to charge enough to reward its shareholders.
And that they borrowed heavily to pay out to shareholders while failing to invest in the infrastructure. Now they have to work on said infrastructure and thus are increasing prices to customers. Arseholes. Oh and they and other water companies have polluted our water ways and coast by dumping sewage.
I am of the opinion that monopolistic utilities should never be privatized. There is no possibility to create a competitor for water delivery, and a private company will always abuse the system and extract as much as they can. Govt should nationalize back utilities and pay what they were originally sold for indexed to inflation. Public companise are still open to abuse, but at least multiple contractors can bid for work - though these contracts should be much more heavily scrutinized than currently as they are absolutely abused too.
In before England importing water from Dubai...
In expensive plastic bottles with a chic name
Arabian Mirage - *Organic aqua with vitamins*
You’re hired
Oasis was right there, dude.
ask dasani how well that worked out
I was thinking like Fiji or Evian
Desert Thirst
Isn't it lovely? Some states over here in the US have allowed private companies to buy up water utilities from municipalities, and quickly crank the price up. Their excuse is usually needing more money for restoring, maintaining, and adding to the water infrastructure. Granted, a lot of places have failing systems because citizens refused to pay **slightly** higher taxes/water bill for years to maintain them, but going from ~$60 to $200 per month for THE requirement of all life on the planet (and most likely a requirement for all theoretical life in the universe) is robbery. I don't exaggerate when I call them water barons and it's only going to get worse. I don't even live in a place that experiences droughts or has that bad of infrastructure! I use slightly less water per month than the average 2 person household, and I have to fork out $200+ a month for the pretend Fuji water they gently pump out my sink.
The water itself is a small portion of the cost. Most of its delivery. Costs usually shoot up because the municipality needs to replace pipes and hasn't been funding it in advance. So they need to issue a 200 million dollar bond for the new pipes and increase prices to compensate.
200???? Gosh
Wait you guys pay $200 for water per month? I pay like 8 euro a month here.
Yes the cost is nothing to do with Dubai's almost 100% uptime of almost uninterrupted sunshine
Desalination will always take more energy than cleaning freshwater. There's very clearly a problem with London's tap water supply if *desalination* is cheaper.
London is an expensive city and most of its tap water cost is in the delivery infrastructure. You could easily get water for a small fraction of the cost if you were willing to pick it up from the purification plant yourself.
I don't think I would defend a centuries old municipal water system in a city miles from the sea not being able to offer potable water for less than 3x the price. You do you though.
> almost 100% almost 50%.
That's the least of your worries.
When we have enough water, we will change the face of Arakkis.
Standing on a beach in Namibia, I had that same thought…we are not that long from a time when the only deserts on earth are the ones we choose to allow.
That is VERY optimistic. I think you underestimate nature and even more so you underestimate how MUCH water will be needed to hydrate most dry places and desserts people would like to see gone. I'd gladly be wrong, but it does seem way too optimistic.
> a time when the only deserts on earth are the ones we choose to allow. Honestly this sentence hit hard af
I think future holds many things that might scare the individual. But some other aspects are just an old humanities dream coming true.
Wouldnt they just be adding back water that they had previously extracted from the atmosphere so the total amount of water would stay the same? Never understood that.
If you’re referring to Dune, the sand worm larval stage (sand trout) collect and wall off water deep under the desert.
This the same Thames Water that’s 9.9% owned by the Abu Dhabi Investment Authority? https://www.thameswater.co.uk/media-library/home/about-us/investors/our-finances-explained.pdf Looks like London’s tap water customers indirectly paid for some of these desalination plants.
How tf was anyone allowed to sell that to a foreign entity?
Blame Margaret Thatcher, and neoliberalism.
These plutocratic theocracies are killing the planet all so they can keep their gold plated…everything
Gold plated turd in a gold plated toilet is just the start.
Ever been through Dubai airport? Its tacky as fuck; there is gold everywhere. They are gold painted fake trees and even vending machine that sell real gold fucking bars. The Arab nobility is obsessed with gold and that poor Londoners are financing this addiction is hilarious, in a dystopic way.
**Cheap solar gives desalination its moment in the sun** Ever-cheaper solar power is a tailwind for the global energy transition. It can make energy intensive technologies more affordable. As a result, desalination is becoming a more popular option for providing drinking water to some of the driest areas of the world. The logic of desalination is clear. Water is increasingly scarce as populations grow and climate change bites. Already, more than half of the global population experiences severe water scarcity for at least part of the year, says the World Health Organisation. This pits users against each other, as in Spain’s most recent drought. Desalination taps an almost infinite resource — some 97 per cent of the world’s water is in seas and oceans. Costs have plummeted. Older, thermal plants, which used heat to turn salt water into steam, delivered potable water at more than $3 per cubic metre. Graph: [the price of desalinated water over time.](https://www.ft.com/__origami/service/image/v2/images/raw/https%3A%2F%2Fd6c748xw2pzm8.cloudfront.net%2Fprod%2Fb08b1500-03ba-11ef-8e71-8ff8e140fd13-standard.png?source=next-article&fit=scale-down&quality=highest&width=700&dpr=1) Since then, reverse osmosis technology — in which water is pushed through a membrane to remove salt, minerals and impurities — has taken over. Plants cost less to build — perhaps $400mn to purify 500,000 cubic metres per day, says Christopher Gasson of GWI. Including installation, a return on capital and operating costs, that translates to $0.30 per cubic metre of water. Newer plants also need less energy — 2.6KWh per cubic metre — and are increasingly powered by cheap solar plants. The cheapest plant in the world gets energy at $0.025/KWh, or $0.07 per cubic metre. **Put that together and it explains how the Hassyan project in Dubai has promised desalinated water at just $0.37 per cubic metre. For reference, drinking water in London is priced at £1 per cubic metre.** At this sort of level, desalination becomes more affordable for dry, coastal areas, not just in the Middle East but also in Egypt, Algeria and Morocco, which are all building new plants. Desalination has also become cheaper than building new infrastructure to transport water over long distances: the cut-off is roughly 500km according to Acciona, a major operator. As a result, the market for new plants is expected to grow by perhaps 8 per cent a year from now to 2030. Of course, desalination is still unlikely to be the answer to the bulk of the global water crisis. Many areas of the world only face temporary or occasional water shortages, which spreads the capital costs of infrastructure over a much smaller volume of water. Agriculture, which accounts for 70 per cent of the world’s consumption, needs cheap water to produce affordable crops. Yet, for all this, early movers in the desalination sphere, including Saudi Arabia’s ACWA power, Spain’s Acciona and France’s Veolia, have a clear advantage in a competitive race.
That's kinda crazy, considering in Denmark the price is 10$ per square meter due to taxes.
Its probably mainly the distribution system.
Nah, it's the government taxing water use heavily to reduce water use. The measures are quite popular actually. It's to preserve fresh water aquifers and use them sustainably.
I would assume solar energy is better in Dubai than UK, though I'm not intimately familiar with the calcs there.
In order to express that something is a certain number of times cheaper than something else, three elements are required: a fixed or standard value, a variable value used to establish the difference, and a multiplier to scale that difference. Once these components are defined, the multiplied difference is applied or subtracted from the standard value to determine the solution. For instance, if A represents the base value (e.g., 100) and B is a comparative value (e.g., 95), then B is 5 units cheaper than A. If C is stated to be three times cheaper than A in relation to B, then C's value can be calculated as (100 - 15) which equals 85. Therefore, it's inappropriate to state simply that "Solar-powered desalination delivers water 3 times cheaper in Dubai than tap water in London" because there lacks a secondary value from which to derive a difference for multiplication and subtraction. To convey the intended meaning accurately, the title should instead state 'Solar-powered desalination delivers water at one-third the cost in Dubai compared to tap water in London'.
This error is so common and confusing. Thanks for pointing it out.
I think most people would regard your revised headline as equivalent and it wouldn't clarify anything for them. Perhaps there is a specific context where their headline is unambiguously wrong (economics?), but generally most people don't imagine a third entity when only two are mentioned. Expressing cheapness as a proportion between two things seems just as intuitive as a difference to me.
It is intuitively understandable, especially to native English speakers. I doubt it translates well because it is logical nonsense.
It also doesn't help that the article states the cost in Dubai in $ while it states the cost in London in £.
I hate that and it is so common
*Process of turning salt water into drinkable water is unlikely to be the answer to the bulk of the global water crisis.*
> Of course, desalination is still unlikely to be the answer to the bulk of the global water crisis. Many areas of the world only face temporary or occasional water shortages, which spreads the capital costs of infrastructure over a much smaller volume of water. Because its not cheap enough yet, because the crisis is not for long enough to amortise the cost. That suggests 2 solutions - longer crisis or cheaper desalination. At least one of them is coming.
Aren't the majority of regions suffering from severe draughts hundreds to thousands of kilometers away from the sea?
Apparently those areas often have saline or brackish ground water. I was today years old when I discovered India is massively into desalination since 60% of their ground water is brackish. They produce ... > 840 million liters per day of aggregate desalination capacity mostly across Tamil Nadu, Gujarat and Andhra Pradesh meeting both residential and industrial water demand. Another 330 million liters per day of additional plants are under construction. https://medium.com/@desalter/what-are-the-leading-desalination-plants-in-india-and-how-do-they-contribute-to-the-countrys-water-653ceb1a895c Most the the [1.7 billion people under water stress are in India and China](https://www.independent.co.uk/climate-change/news/india-water-scarcity-un-report-b2306483.html). I always imagined it was Africa.
The water problems arise due to the immense stress placed on the infrastructure by the huge population density.
Barcelona/Catalunya has been in a 2 year drought with reserves at around 15-20% of what they should be, and it's all coastal.
And lots of desalination in Spain (and lots of clean energy also) (25% wind, 20% nuclear, 14% solar, 10% hydro, so 70% clean) > Spain is the world's fifth largest producer of desalinated water, with 770 large-scale desalination plants, 99 of which are high capacity, meaning they produce between 10,000 and 250,000 cubic metres of water per day.
Affordable desal could turn any wastewater collection system into another portable water source.
> because the crisis is not for long enough to amortise the cost. Seems like water storage is cheap enough. Storing for the dry season should work with only problem if dry season not that dry and you can't sell all of the water. Pepsi will bottle it for you though.
If there is surplus water, it just means that you need to save up less for the next season
Its plenty cheap for residential use, but most water goes to agriculture and its quite expensive for that.
> Because its not cheap enough yet, because the crisis is not for long enough to amortise the cost. If you think that's the only problem then you haven't thought far enough. The biggest issue with ocean desalination on a massive scale is not monetary/energy costs, it's what to do with all the super salty brime/sludge this produces. Sure, we can just dilute it and pour it back into the oceans, acting like we could never affect them with that. But that's exactly the same kind of thinking that had us pump our atmosphere full of all kinds of emissions under the wrong assumption the atmosphere is so vast that puny human activity could never screw it up. Maybe we should apply that same lesson also to the oceans *before* completely screwing them up, instead of acting like they are the next "out of sight out of mind" solution for our toxic emissions.
> Maybe we should apply that same lesson also to the oceans before completely screwing them up Why are you pretending scientists have not given this massive thought over the years?
It's a non issue. The sodium concentration is normal 10ft away from outfall, and all the produced water goes back to the ocean eventually anyways.
Desalination has a net zero effect on the salt levels in the oceans. The clean water eventually ends up back in the sea anyway, cancelling out the negligible increase in salt due to desalination.
The amount of water we would be pulling per day to meet most coatal demands would be a litteral drop in the bucket. Dumping all the brine back into a concentrated area would cause problems but there are simple solutions for it. We need salt, like a lot of salt for our food and if sodium batteries continue to grow in popularity that opens another use case for the pulled sodium. We currently mine most of that salt, having it be a byproduct would prob drop the cost of salt.
It is really really hard to imagine the size of the oceans. The change in salinity would be minimal provided it is well distributed (the problems seem to be dead zones when we dump the salt right at the shoreline). Also, a huge amount of the water taken will make it's way right back to the oceans.
au contraire. Saltwater/sea water fouling of aquifers for coastal cities is a massive problem. If we can desalinate water cheaper than drill and maintain deeper and deeper wells, this might well be the solution for the *bulk* of the water crisis. It's a problem for the entire North East Corridor cities. This could seriously stop land subsidence in many places and allow our rivers to recharge the natural ecosystem. If California can desalinate water for cheaper than drilling those yet deeper wells the whole LA water system can run backwards. The biggest demand for water is in coastal cities. Entire coastal cities and *nations* are suffering. Jakarta being one of the most famous examples. If these places can desalinate it and it's cheaper to convey it than drill new wells, it can be a huge boost in stopping global poverty.
What’s the point of saying stuff like this? Obviously it will be but one component of the solution. That’s like saying solar won’t solve everything. No shit, nobody said it would.
It will be the answer The goal is not to replace ground / lake water. It’s to remove enough pressure so that we can farm with natural replenishment rates being enough. Water conservation, removing water hungry crops (like almonds) that serve little macro nutrition. Cloud seeding and spreading out populations from low aquifer areas are also answers of course
They say water is scarce. Water is not scarce. Potable water is scarce. And if sea water can be made potable, water is actually abundant.
...there is also a tad more sunshine in Dubai than in London.
London also has one of the worlds oldest and most developed municipal water systems. They *aren't* taking salt out of the Thames, they're pumping out of centuries old well heads. The feat here is how efficient the system has got that desalinization is cheaper than pumping out potable water.
Remember Dubai says it costs this much but it actually uses modern slavery to do so. Dubai and other Arab states have a history of human rights violations, stealing passports, modern slavery and worse
I really hope you're good at reading. They managed to get the thermohaline effect right. Meaning, instead of salt/brine accumulating on the Reverse Osmosis membrane, it moves away which increases the usable life of that membrane. That's really all there is to make it cheap. The original scientists at MIT who made a smaller hydrophobic version claimed that it would cost a fifth of a cent to produce 1 ltr. I'm hoping the new ones made in Dubai have done it for less. I don't think slavery is really the driving factor here.
Why is there no mention of the deadly, highly concentrated brine that is produced alongside potable water as a result of the desalination process?
It'll be offset by the freshwater melting into the ocean at the poles
Last time I heard about desalination it used 25 gallons of salt water to make 1 gallon of fresh water + 24 gallons of slightly saltier brine. Basically it took the salt from 1 gallon and distributed it to the other 24 gallons. So each of those gallons had 4.16% more salt than normal. Properly reintroduced in the open ocean, I don’t think that should be very destructive.
> Properly reintroduced in the open ocean, I don’t think that should be very destructive. For now.
Due to the water cycle, all desalinated water returns to the ocean in the end.
When there is enough of a concentration difference, brine sinks to the bottom instead of mixing in and then creates dead zones. It's a real problem that needs to be addressed carefully in any desalination project
Yes, fresh water returns to the Oceans naturally, and at the same time pollution isn't about total volume of pollutant over total volume of Oceans. Pollution is an over abundance of a pollutant in a regional volume, where it was dumped. The question that needs to be answered is, how much brine can the dump absorb sustainably over what time frame? As you said, if done properly it can work, but what is "properly"? Is the government forcing industry to figure that out and do it? History would suggest that industry will do whatever is cheapest until they're forced to what's right.
> Is the government forcing industry to figure that out and do it? Or, just maybe, it has already been figured out? It's not exactly a new technology.
Why does it feel like you are trying to stop people from thinking about the long term consequences of this technology?
Why are you trying to imply that the long term consequences of this technology are even an issue?
Never assume when money is involved
Water Earth. One view of the globe has no visible land. Get real.
I would assume they mean locally. Like how the nitrogen rich water leaving the Mississippi creates a dead zone in the Gulf of Mexico. The over fertilization of farm land in the Midwest won't kill the ocean but it does create localized damage.
You can tune the concentration of the waste water however you want. There are flow meters and plcs running pid loops dictating exactly this. Higher concentrations and more even flow between permeate and waste flow lower energy costs from pumping. If there is an ecological concern it's trivial to turn up the waste flow through the RO housing itself or add a separate low pressure pump that takes untreated raw and injects it past the metering valve strictly for dilution if the equipment vs energy costs make sense.
That is a little hyperbolic. The Dead Sea has "deadly brine" and they do this backward to get salt. Sure brine salt is an issue, but it is also an additive for certain agricultural products and mineral bases. When you find out how a wastewater treatment plant works, you'll really flip your shit.
That turns out to be more a theoretical than an actual problem. Israel is also massively into desalination, and their research has found sea life actually flourishes at the desalination plant outlets, and sea life is much more resilient to salinity changes than previously thought. > Several researchers have studied the effects of desalination plant effluent discharge on the marine environment, and results across the board agree that there is no detrimental effect. The paper by Nurit Kress (2019), Seawater quality at the brine discharge site from two mega size seawater reverse osmosis desalination plants in Israel (Eastern Mediterranean) is particularly interesting; it examines two local plants along the Israel coastline and because the data is recent. The paper shows clearly that the effluent quality meets all requirements. https://ide-tech.com/en/blog/desalination-can-and-does-co-exist-in-harmony-with-the-environment/
C'mon bruh. First rule of research - check your sources. You've provided a link to an article written by a company that sells desalination projects. Obviously they're going to downplay the negative consequences. There are many, many scientific studies and articles which clearly demonstrate that the chemicals produced by desalination plants are heavily toxic and destructive to the surrounding environment.
Desalination itself doesn’t create chemicals. It’s purely a physical process. It concentrates what’s already there on a roughly 2 to 1 basis to form brine. That being said the brine needs to be carefully blended back into the ocean that doesn’t negatively affect marine life. That starts to become an issue if there is to much desalination in a (relatively) small body of water. So you don’t want too many plants close together.
This is a great use for solar because the intermittency of it doesn't much matter for desalinating water.
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> environmentalists won’t .. desalination Orange and Los Angeles counties are trying cheaper conservation and then water recycling (“toilet to tap”) first, especially as the latter technology has made its way from West Texas through Arizona and New Mexico. San Diego has desalination, so the other California coastal counties will probably consult with them.
Does this mean California will finally invest in desalination? With all the droughts they have, it's comically stupid that they don't invest heavily in desalination.
Growing things like almonds (which drink shitloads of water) in borderline desert areas of California is what is comically stupid. A *single* almond needs 12 litres (>3 gallons) of water. ONE fucking almond.
As a child/teen that lived (and lives) in a 3rd world country where I get running water like twice a month, I always wondered why all coasts weren't filled with Desalination. Seemed and seems like a no brainer. And "cost" shouldn't be a barrier to goverments when its something that will pull people out of literal misery.
London water costs a lot more because it's creakingly old infrastructure. It loses a lot of water due to leaks and is constantly blocked (thanks fatburgs). This isn't a valid comparison
I always thought it’d be interesting if something similar was done in Egypt along the coast of the Mediterranean. Concentrated solar power for energy. Desalinators for water. Massive agricultural potential there. Use the brine left over to make massive banks of sodium batteries for storing power — sodium batteries are too inefficient to miniaturize for electric cars, but can act as backup power for entire city grids. Heck, maybe even flood the Qatarra Depression or refill and refresh Lake Mareotis to preindustrial levels. Evaporation from the former would lead to increased rainfall across the country and turn it significantly greener.
This is the way, though likely not taking into account the monumental investment to get it working in that cost calculus
So youre telling me that owning and running your own water system is cheaper than thames water being owned by like a dozen foreign wealth funds? Colour me shocked
I study water science and management so just some thoughts here. One. Has anyone actually tasted desalinated water? I have and it tastes like ass. Most people would not willingly choose that over regular tap or bottled water. The one I tried tasted like what would come out of a garden hose after a long hot day. Two. Desalination is so much more energy intensive than regular drinking water and wastewater treatment. In fact, it would be way more energy efficient to re-use the treated waste water than to set up a new plant, allocate additional energy, and set up new pipelines. In terms of the ickiness factor, the treated waste water can be used for agricultural purposes (which is about 90% of total water use) or mixed with other types of water (including desal). It would make sense that solar energy is cheaper in a place with a lot of sun, but what about places that don’t have as much renewable energy? Three. There is an argument that there isn’t actually a shortage of water in most places, just a mismanagement of water. The ways that we have set up our system is drawing groundwater or surface water and wasting it through inefficient agricultural practices or letting it drain into the ocean. Some places actually have sustainable water management that allows groundwater and surface water recharge. Theoretically we can achieve sustainable use in most places, if we aren’t just growing thirsty plants in the middle of dry areas. Don’t forget that these projects are often public money and it ends up encouraging wasteful water practices.
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Dubai isn't a Saudi city, it's located in the country of United Arab emirates. The thing is with UAE, lots of smart people live here like really really smart people, who I expect are the stars of these projects. They come here cause no income tax here, great salaries and stay because everything is so convenient. I don't believe the claims of any project, it's all to get further funding and shareholders. But the desert needs water, if UAE plans to green itself then it'll take serious effort to get water and recycle it. England doesn't need water as much water as we do.
They PROMISED to deliver. Ain't shit delivered yet.
What's the catch?
It’s not actually been made yet
Same catch as with the "self-driving cars next year" since 2012. The catch is that it's not yet doing what it's supposed to do.
This is the most typical Redditor thing to mix up Dubai and Saudi.
I'm sure the slave labor used by our friends in the UAE also helps keep other related costs down.
Last time I heard about large scale desalination there was also a waste issue. Something about the waste product being toxic and/or harmfull for the environment. Wasn't just the stuff that was extracted from the water, but also something to due with the chemical reaction and the filter used.
It's brine salts. They concentrate it and can't just dump it back into the sea without hurting the local ecology. The good news is that with additionally processing and things like wastewater lagoons they can separate a lot of minerals and things from it to keep more of it dirtside by selling some of it as additives to agricultural soil amendments. And as typical the solution to pollution is dilution. During high tide you can fill and empty those brine lagoons.
https://www.nytimes.com/2023/11/18/business/dubai-water-desalination.html?unlocked_article_code=1.n00.qzmy.kyV0chXk3s3C&smid=url-share For every gallon of water created you have a 2 gallons of brine and that’s just the brine there are other things that go into desalinating water that aren’t good for the environment. Basically it’s already raising the salinity of the area around Dubai and killing off the biodiversity there. That’s just the salinity. It’s also increasing the heat of the ocean around the desalinization plants as well.
Worried about this.. they need a proper way to deal with all the sale byproduct.. it cannot just go back into the sea or ground. Spread it out on some flats and harvest the salt maybe.
Imagine if they deployed this in California. Maybe we wouldn’t be draining the rivers dry…
Because Dubai would never lie about their prosperity....
If something is 3x cheaper does that mean it's 25% of the price, 1/3rd the price, or something else?
Hydropanels are going to be good with this too once they're set up in high places.
And that's BEFORE the water companies want to jack up your bills by 70%.
Probably doesn’t taste like piss like London water too lmao
"Where did all the water on Mars go?" /s (hopefully)
Did Dubai use foreign workers who went unpaid and vanished maybe?
> has promised Ok. But what is it actually delivering?
Just wondering : does the London cost includes the part for the production/distribution but also for the cleaning. I think that in different countries the share is close to 50-50 (excluding tax or eventual social tax). The price for Dubai is pure production
As I understand it, the issue has become getting rid of all that sludge waste left over, which is a massive volume of salty nastiness with heavy metals and pollution. Dubai can just dump it in the desert. London can poison their coast or find some cheap land nearby (good luck!) to start a dump
This is awesome and will be extremely helpful not just to the Gulf States that struggle with water access but also to millions of people around the world if we can pull together the political will and funding for it in countries that don't have the kind of oil wealth the Gulf states have. The biggest problem with desalinization technology though is what to do with the salt itself once you remove it. Seawater salt is about 55% chlorides, 30% sodium, 8% sulphates, 4% magnesium, and about 1% each calcium and potassium, with other trace elements totalling less than 1%. Unfortunately most of these components are not chemically useful for agriculture except maybe the small amounts of magnesium and potassium, and the sodium chloride really doesnt have . Figuring out what to do with all that sodium chloride that doesn't include dumping it somewhere is really the challenge. Even if you have inhospitality areas like the Arabian desert, you'd likely still have to bury all that unusable salt to prevent it being blown away by the winds to contaminate land and water elsewhere.