The author, who holds a PhD from Caltech, proposes taking advantage of the decreasing cost of solar power to enable a new age of clean water abundance in California, sustainably, with the potential for massive revenues and profits at all steps in the value chain. Even if the author's calculations are off by a factor of two, the proposal looks like it could work. At a minimum, it merits serious consideration. The status quo will not solve our pressing environmental problems.
The main challenge an innovative large-scale project like this one would face, I think, is a regulatory bureaucracy which to me often seems like it was designed for the technologies and infrastructure of the 20th century, not for those of the 21st century. I shudder to think of, say, inspectors who are highly trained on narrow technical matters, but who lack a fundamental, multi-disciplinary, big-picture view of the entire project, deciding whether to approve individual tiny little parts of it.
Skepticism is warranted. The track record of "Oh, we don't have to change our incredibly wasteful and unsustainable ways after all, technology will fix things!" has been... poor.
It's a very interesting idea - but practically speaking, the kind of water volumes needed for drinking and bathing water for a city like Las Vegas are dwarfed by the volumes needed for the farming of sugar beets, alfalfa for dairy, golf course grass maintenance, etc. If current trends in the American Southwest continue, extreme water conservation will have to become the norm (the other alternative being depopulation of the region).
Yeah we can't realistically get better water outcomes by only changing out supply. We have to change our usage too. Farms should be converting to crops that have lower water usage, and food manufacturers should be converting to foods that make use of those crops.
Maybe we should not use so much water (for agriculture) in a desert area at the first place. Feels like we are putting fixes on top of fixes.
"A Saudi Arabian company grows alfalfa on farmland in Arizona and California and sends it overseas to feed the country's cows. These legal farming operations extract groundwater in Arizona and water from the Colorado River across the border in California, experts say." source: https://www.maxwell.syr.edu/news/article/koch-discusses-saud...
Maybe if we stop exporting Colorado water packed in alfalfa and other agri-products, we would have enough water ?
Exporting water through alfalfa to Saudi Arabia who indeed banned alfalfa fields in their country because it was consuming just too much water, is one of the problem we should fix before installing PV and batteries in the desert, and dump concentrated brine somewhere.
I know he inputs some numbers, but I am just supremely skeptical of them. If solar + batteries + RO plants could produce water at a price that made agriculture economically viable, then I just don't see how it wouldn't already be happening. Or at the very least be being proposed more broadly than some random guys blog.
If I understand correctly, it is his plan for extracting value from the brine which represents the biggest unknown/the most need for development, while also being the thing that makes it all make sense. I've never heard of any of the existing worlds desal plants doing this, so either it must be harder than he supposes or else he must think that every single person in charge of a desal plant the world over is an idiot.
Don't get me wrong, I realize that sometimes people miss obvious things. And sometimes, there really is a $100 bill on the ground, despite what the apocryphal economist would have you believe.
But in this case, areas like that are what I need to be convinced of. While it's maybe true, you don't just get to assert it.
As they say "What can be asserted without evidence can be dismissed without evidence".
> If solar + batteries + RO plants could produce water at a price that made agriculture economically viable, then I just don't see how it wouldn't already be happening.
The costs of solar and batteries have been dropping for decades. It's 100% believable that this type of thing has been considered, repeatedly, and discarded as economically infeasible, leading to the major players in the field choosing to ignore it for a while—but that the costs have now dropped enough that the economics work out.
Agree with the skepticism, and furthermore if this were such a killer moneymaker you'd expect multiple commercial efforts in this space already.
But this is California - there may be reasons that are not economic or technical that have prevented anyone from trying to develop or pursue such an idea. The concentrated salt-brine discharge, for example, may be impossible to get environmental approval for at these volumes.
Israel is, I believe, the place in the world that has the most desal, and is actually already using it for ag. I'm not familiar with domestic/development policy in Israel, but I have trouble believing it's as restrictive as the CA. So not only has CA not already done it, but neither has Israel, who, at the very least must have different roadblocks.
The point is, it's not only California (which I agree is pretty anti-development and where this plausibly might be disallowed even if it did make economic sense) that is leaving this supposed $100 bill on the ground.
Are we using that definition of "world" that somehow excludes any other country outside the western alliance? Saudi Arabia and six other countries have more seawater desalination capacity than Israel.
I put "believe" specifically because I knew I didn't know much on the topic and they were a country I knew used a lot. I was very intentionally signalling my lack of certainty about that sentence. A simple correction rather than an assumption of....whatever the hell it is you are vaguely accusing me of would have been much more helpful.
That being said, thanks for the heads up! However, it really just strengthens my point that even more countries are using desal and not mining the brine.
The cost of solar dropped by 90% between 2010 and 2020, and the cost of panels fell by 14% last year. Batteries were just straight up not a thing until 2019: California's grid-scale battery storage capacity has been doubling every year since then.
Putting together the solar panels, the battery, the desalination plant, and the brine plant, he's proposing a $42 billion dollar project that has only been economically feasible for a year or two now. I'm not surprised that it hasn't been built yet.
You realize that desal is already being used in various places in the world, including for (secondarily) ag, right? So there are already places producing the brine. Why aren't they mining it for value? As far as I'm aware, it is universally being discharged.
So either it's harder to extract value from it than this person supposes or no one else has ever thought to try and get value from it.
The second one isn't impossible but I'm not just going to believe it with no evidence.
I think the biggest thing this new wave of water desalinization evangelists are latching onto is tightly integrating green energy sources into the process to effectively offset the energy costs (economically and ecologically). But honestly I can't tell if it's really a new generation of designs that'll make desalinization feasible where it currently isn't, or just another example of green washing.
NYT daily had a relevant podcast episode on this (https://www.nytimes.com/2023/09/01/podcasts/the-daily/water-...?). Discussion centered around using the water for Arizona, not California. (I'm unable to speak of the relative merits of pumping the water from one state to another).
General takeaways:
Proponents of the solution seemed to understate challenges and risks associated with:
1. The pipeline itself (i.e., where to build it)
2. The disposal of brine solution into the Gulf of California.
3. Cooperation with Mexico.
That's not to say the challenges couldn't be addressed, but discussion of such challenges is noticeably absent from the original article.
Yeah this seems like a big challenge. Even if the Gulf of California is closer, or if it's all downhill, the requirement for international cooperation seems like it would make this a much more complex option than just using the Pacific. Plus if I were Mexico, I'd honestly be looking at the Salton Sea disaster, noticing that some new plan calls for putting salt down in my neighborhood instead of off the LA or San Diego coast.. sounds sketchy.
Meanwhile, the Arizona version of this plan is understandable.. Phoenix is thirsty, they have no coast, it's shorter to get to one in Mexico than California and anyway they might actually have better luck dealing with Mexico than California. But can anyone explain briefly why California would want or need the plan to involve Mexico?
> The solar panels convert wasted sunlight into electricity, one of the most useful forms of energy, at the lowest cost ever in human history. The batteries make this power available at night, enabling 100% utilization of the higher capex systems downstream. The RO desal plant uses this power to strip salt out of fresh water
I wonder if you could store the energy as pressure instead of electricity in batteries.
From what I gather[1], the biggest energy draw in reverse osmosis is pressurizing the water to force it through the RO filters. So, while the sun is shining, fill a tank halfway with salty water, then use solar energy to run pumps to pressurize air above the water. When the sun isn't shining, you now have pressurized water you can let through the RO filters.
Compared to a regular RO plant, this requires high-pressure storage tanks and additional pumps. I'm unsure whether that costs less than batteries or not.
Another part of the analysis is that, if you do build the batteries, they can earn extra money with a side gig stabilizing the grid. Occasionally, when grid conditions get very gnarly, you could shut down the RO plant for a few hours and make a quick buck selling your battery power on the market.
Alternatively, you could pump the water uphill during the day and let gravity supply the energy to force it through the RO filters at night. This means you'll have to build a special reservoir for pre-treated salty water somewhere, though, and you need a lot of pressure, so it would need to be at a high elevation.
A fundamental challenge with storing pressure is that water is essentially incompressible. This means that you can’t build a 1000 gallon tank and store any useful amount of energy in the form of pressurized water in that tank.
Mathematically, it’s easy to forget that the PV term in enthalpy is a mathematical trick, not a physical thing, and that it mostly does a nice job explaining physical things when P = atmospheric pressure.
If you want to store, say, 100psi water, the energy you care about is P times delta V, so you need some thing that can change its volume easily, cheaply, and reversibly while under pressure. As a practical matter, this means compressed air or maybe springs. So that water “pressure tank” is actually an air pressure tank that happens to have some water in it too.
There’s nothing wrong with storing pressurized air, except that it’s a heck of a lot more dangerous than storing pressurized water due to the fact that it really does have energy stored in it. (There’s a reason that a PVC pipe filled with 80psi water is a common thing in houses and the main danger is that water escapes if it breaks. A pipe full of 80 psi air is quite hazardous.) There are startups that have played with compressed air energy storage. The resulting gizmos are large.
I would expect a RO plant that is optimized for intermittent use without any energy storage at all to end up being a viable alternative to energy storage, but maybe batteries will end up being cheap enough that this isn’t worthwhile.
Batteries have proven extremely resistant to the scaling of solar panels. I would love to be wrong about this, but overwhelmingly people with an agenda just kind of hand-wave past grid scale energy storage problems that we have generations of evidence against being easily or cheaply solvable.
The thing about this plan that I love though, is that who cares if the desal plant runs at night? Desalination can take all of the power you can feed it and then some, and if it shuts off after sundown, who cares? Stop filling your freshwater reservoir until morning, at which point you just run flat out all over again.
It does matter, though. Suppose you need X amount of fresh water output per month. And suppose that for Y dollars, you can build a plant that supplies X if it runs 24 hours per day.
If, instead, you can only run your plant 8 hours per day instead of 24, then you need to build a plant three times as big, which costs 3Y dollars.
This is where batteries (or other energy storage) may become useful. If you can build them for less than 2Y dollars, then you can build the whole system for cheaper.
My question is: should it actually cost 3Y? Sure, if you take an off-the-shelf design and triple it, it will cost around three times as much.
But there should be at least some efficiencies that can be gained. For example, energy conversion is not cheap. Rather than building solar inverters that produce 480VAC and using 480VAC pumps or pump drives, what if the pumps ran on DC?
Or, for more fanciness, what if the pump drives were themselves the MPPTs? Have the solar panels arranged so they produce a sufficient voltage for the motor drive bus even at minimum output, and make the drivers smart enough to run the right number of pumps at the right power and to do so while tracking the maximum power point? That’s a lot of power electronics that could be avoided.
Also, if a plant is willing to store a day’s worth of seawater and brine, then the intake and discharge systems only need to be sized for maximum daily average flow, not peak sunshine flow.
What I'm saying is that the freshwater reservoir is a totally free grid scale battery for a desal plant. No need to save it, just make fresh water while the sun shines and drink it whenever.
Yeah, I'm just saying-- a big desalination plant is a solved problem. Grid scale energy storage has been ten years off for almost as long as nuclear fusion. The original author just hand waves their way through what would be the biggest energy breakthrough in a hundred years to save a couple bucks running a desalination plant.
I don't mean some grander point about environmentalism or development, I mean that I have specifically examined solar desalination for the Imperial Valley and he's missed a much simpler way to get the water from point A to point B.
See, there's this other basin in nearby Mexico called Laguna de Salada which is basically an empty salt flat about ten meters below sea level. If you flood that by dredging a canal (about 10-20 km and not very high), you only have to transport the desalinated water about five kilometers to get it into the Imperial Valley drainage basin.
There's no need to back up the Colorado and mess up what's left of the delta, plus you can put the rejected brine back into the now Golfo de Salada where it will mix more slowly and (hopefully) less destructively with the seawater to the south. The area will still be something of a dead zone, but it would only replace an existing dead zone.
I am by no means a desalination expert, but pumping vast amount of a salty water 100+ kilometers (Pacific Coast) or from the Sea of Cortez (closer to 200kms) seems strange as compared to building the desalination plant on the shore and transfer the electricity generated in the desert.
One can also replace some drinking or agricultural water used way closer to the coast in CA from the Colorado Basin with the newly desalinated one.
Way less pumping. Or do I miss something?
I have spend few years in San Diego doing hikes inland. There are decently sized mountains in the desert between say Borrego Springs and the coast. Not an optimal area to build a pipeline cheaply.
Pipe going along Colorado river should have less bumpy course but there is a biosfere reserve just on the top of Baja California. Not a good spot to suck giant volumes of sea water, even less so to construct a pipeline or heavens forbid dump the concentrated brine.
Apart from whether the economics make sense brine disposal from desalinization is a big issue. Waste with high salt concentrations can wipe out marine life - it would be nice if this piece took the issue a little more seriously. It's a continuing problem in the Canary Islands which are dependent on desalinization plants:
"Rejected brine is a serious threat to marine ecosystems, causing negative effects on both flora and fauna. This is especially so when the optimal initial high dilution capacity is lacking in the discharge system. Consequently, brine discharge plumes spread over large areas of the sea floor and modify the structure and distribution of benthic communities such as seagrass habitats.
...
Rejected brine disposal costs are between 5 and 33% of the whole desalinization process, depending on the characteristics of the brine, its pretreatment level before disposal, disposal method, and volume"
from: Jiménez-Arias, D., Morales-Sierra, S., García-Machado, F.J., García-García, A.L., Luis, J.C., Valdés, F., Sandalio, L.M., Hernández-Suárez, M. & Borges, A.A. 2020, "Rejected brine recycling in hydroponic and thermo-solar evaporation systems for leisure and tourist facilities. Changing waste into raw material", Desalination, vol. 496, pp. 114443.
> Dump the brine water in engineered desert fields where it will evaporate and deposit salt reserves.
Honestly, the Salton Sea would be a great place to dump the brine. It would keep the water levels up and reduce the respiratory issues caused by drying, and any ecosystem to be destroyed has been thoroughly destroyed for decades.
Nix the "turn the manmade salt lake to a manmade fresh lake" plan, and use the created freshwater for agriculture directly, or send it off to LA, or do anything with it that isn't "refill the accidental lake that already has evaporation and pollution issues". It's a salt lake, use it as one.
This is something I still don't understand about the original plan: Where is the Salton Sea expected to get more water from on an ongoing basis? If you keep extracting from it and not refilling it, it's just going to keep getting smaller and saltier. Agriculture isn't going to put back out as much as it takes in (the plants need it, after all). Sure, you can drag it out a few more years with desal, but eventually it's not going to be much of a sea, just a salty pile.
AFAICT, water is pumped from both the Sea of Cortez & the Salton Sea to a desal plant. The fresh water is used for irrigation etc, and the runoff from primary use replenishes the Salton.
The Salton sea is the home of a huge lithium deposit, and it's unlikely that anything but geothermal and lithium mining will happen there in the near future. Certainly not "restoration" to what it was when it was accidentally created.
My understanding is that the lithium in the salton sea is relatively less accessible than other nearby lithium deposits, such as the new mine starting up in northern Nevada. Sort of nearby I suppose.
Between that and the increasing availability of sodium ion batteries it may never actually be economical to mine the Salton Sea, especially considering people actually live nearby and would be affected by the mine; unlike the mines in northern Nevada.
They'd be mining the brine in which the lithium is dissolved as well as constructing geothermal plants to take advantage of the temperature of the liquid.
Huh, I guess I was mistaken that restoration on the Salton Sea was already in progress. I've seen large flocks of birds in and around it and assumed there was food for them in it. But it sounds like no, it's still horrible.
Is there a way to know how much to care? We do all sorts of things that displace species, so having some way of contextualizing and weighting the harm against the benefit would be helpful.
Seems to me it would initially be a narrowly scoped to the immediate outflow. As the brine dissipates I assume it will be normalized by the rest of the ocean as it's diluted.
However, as with all human endeavours, scaling up will scale up the problem. And we won't pay attention to that until it's a huge issue.
Not the OP, but I think humans in general find it difficult to scale up. Whether in software or manufacturing or politics or environmental issues, we're much more equipped to deal with 1 or 10 of something than 100,000 or 1 trillion of it.
At the end of the day we're still limited by our biology and brains, evolved for very different setting than the world we now live in. We try and we get by but by and large we're not doing great at large scale issues, whether it's jobs or housing or healthcare or saving the planet or just plain getting along with each other.
We're primates adapted for small group living in local communities, abruptly given way more power than our biology was designed for. Is that misanthropic? I dunno. If dolphins had opposable thumbs, they'd probably have gotten themselves into a similar bind.
The Salton Sea in its current iteration was created by the failure of an irrigation canal. Before that there was no Salton Sea as we know it or tourist area.
This is necessarily a value judgment, isn't it? There are tools like lifecycle analyses and environmental impact reports and threatened species lists that can help estimate/enumerate impacts. But ultimately how much to care is a personal question, and people are going to disagree over whether some small fish or rare owl or fluffy panda is worth more or less than someone's job or a local industry or just some other charismatic species.
Species will always come and go, and they're going to die off faster than we can protect them, sadly. We only get to decide which ones to prioritize, at different personal, local, national, global levels etc.
I would start by wanting to know about the impact and benefit relative to other activities which we already do. Like how's it compare to various flavors of farming?
There's a database for California Environmental Quality Act reports, I think (Environmental Impact Reports? Statements? One is federal and the other is state, can't remember which is which). That probably have similar solar farms you can look at. Not sure about huge desal projects. Maybe overseas?
I'll try to find some analyses this weekend if I can.
> RO desal splits the incoming ~3% salinity stream into two halves, one fresh and one ~6% salinity. This concentrated brine is fed to adjacent brine processing facilities (ideally in both countries) that exploit the region’s abundant solar and geothermal energy to extract potentially millions of tonnes of lithium, sodium, magnesium, chloride, and other metals found in sea water. The resulting depleted brine is piped back to the ocean where it is thoroughly mixed with sea water and discharged.
Casey's proposing we mine the brine for useful minerals. You're right he's glossing over details, but a citation addressing the economics of brine disposal with his proposed processing would add more to the discussion.
We just simply don't need that much brine for useful minerals -- it's a huge cost and you'll be left with massive piles of mostly useless salt.
On one of my hard drives, I've got an engineering / construction plan for a moderately sized intake + discharge for a small RO facility that would've passed muster in Australia, which has pretty reasonable environmental protections. Round numbers - the intake would have cost $25 million and the discharge more like $75 million. You need a massive structure to be able to emit that brine back into the environment in a way that doesn't just nuke the surrounding marine life. Huge pipes + check valves + cascading discharges, all either on the ocean floor if there aren't reefs and other sensitive areas or even worse from a cost perspective, tunneled out to a depth that can handle the amount of salt.
Seawater is ~35g/L of TDS - the author is talking about 5 million acre feet of desal - what's that, 20 million tons of salt annually?
This is doable. Many coastal wastewater systems already have large pipes that extend miles to sea (1), and that's a rounding error compared to the many more miles of pipe routing sewage to the plant (2, pg A-3)
“ In general, anthropogenic activities pollute the coastal marine environment, altering the environment’s physiochemical properties and resulting in changes in marine communities. Physiochemical conditions can be altered by the presence of pollutants, hypoxia, organic enrichment, decreased hydrodynamic conditions, and, more recently, brine discharge (de-la-Ossa-Carretero et al., 2016). Salinity elevation in receiving soil and water bodies and the territorial consequences of brine with high total dissolved solids on benthic marine life close to the discharge site are the most important environmental challenges associated with brine disposal (Miri and Chouikhi, 2005; Panagopoulos et al., 2019).”
Lots more detail in the article on studies of specific populations as well as discussion of mitigations and alternatives.
This guy claims that Lithium may be partially responsible for some weight gain in our population, but also, that desalination plants cause extra lithium as well.
If it was mined out, that would be viable, but if not...
Considering that the brine output of a single large-ish plant might be 150,000m³ per day[1], that's a hell of a mine shaft to take it continuously. The rock with the same volume as a day's brine would weigh a million tons. The entire Aberfan spoil tips were only 2 weeks worth of that much volume (2 million cubic metres).
The gigantic Hambach open-pit mine grows by 0.3km³ a year, so that could take it (but it can't take the Saudi million m³/day plant). By the time the mine is depleted, the resulting 18km³ pit would not be filled by our single hypothetical plant for over 300 years, assuming it won't evaporate. Which leads to:
The evaporation pools might work: they'd "only" have to be 3000 acres (12 km²) to gather the 4GW of solar power at 1kW/m² for 8 hours a day to continuously evaporate that much water daily[2]. Which is certainly large, but not completely impossible. But then there's 2 million tonnes of salt per year which will accumulate continuously over time.
[1] the largest is over a million
[2] not including water not bring a perfect absorber of solar energy or differing insolation
In an environment where solar and geothermal electricity are abundant enough to make this work, it would be far easier to condense water straight from the air by refrigeration.
:D and if you scale this to the point where the amount of water vapor in the atmosphere is affected, you can also use some of the abundant energy to boil the ocean to replace that water vapor. :) Same net effect (water is taken from the ocean and salt is not) without actually moving the salt back and forth.
If you desalinate 1 gallon of seawater, and then mix the brine with 10 gallons of seawater, the salt content of that seawater has increased ~10 percent.
If that’s still too much, use 20 gallons.
It’s a matter of spending energy on pumps, but it’s totally doable.
Also, the ocean salt content will not be increased by this, since the desalinated water will eventually make it back to the ocean.
Yeah, but if you’re pulling in water and disposing it from a specific region, eventually the water that you’re pulling in is progressively saltier, and you’re compounding the saltiness of that area.
I’m sure that ocean currents will eventually equalize the salt, but if you’re continuously dumping salt into a specific area, it’s going to make that region of the ocean saltier.
You need pipes to spread it out. And I think you may be underestimating the scale and force of ocean currents. Every tide probably moves more water than California uses in a year.
Crucially but overlooked so far in these threads, is that the proposal does not have brine exiting on the California coast; it has it flowing into the Sea of Cortez.
That should be an obvious non-starter for anyone remotely familiar with the unique geography and ecology of the area.
But where are you getting that pure seawater from? If it's anywhere near the outlet, there's a scale at which the concentrated brine will affect the salinity of your inlet.
It's a community of hackers passionate about the way things work. Picking it apart helps everyone understand the inputs and outputs of a system to understand how feasible it is, and what the tradeoffs are. What would you prefer, a generic "that's nice"?
As far as I can tell, the author just kinda glossed over the brine situation. Some minerals can be sold, but his solution for the excess salt was just to turbulently mix it back into the ocean, if I'm reading correctly. The sibling comments here explain why that isn't trivial (cost and wildlife impacts). I found them illuminating!
Current front page items include a paper on vector databases, an example of AI garbage that showed Amazon in a bad light, a quite in-depth treatment of “Trilinear Point Splatting for Real-Time Radiance Field Rendering” hosted on a PhD’s own github page, you know github, a huge gathering place for hackers to share their code with each other? An article criticizing Unity about banning an open source LGPL application, written by a developer of said open source product, introducing a competing platform to further decentralize the app store landscape, an article critical of Boeing, an article critical of Apple, a radical rocket design, bluetooth mesh networking, an open source python notebook project, an indie developer’s project to run stable diffusion in an iOS app instead of from some corporate server, an article on the ethics of immersive tech, an article on mysticism and empiricism, an article on epistemology…
Yeah, real dull business environment here. I’d totally rather go back to my training on peer performance reviews.
If you can’t find anything interesting on this site, it is a you problem.
"If you run into an asshole in the morning, you ran into an asshole. If you run into assholes all day, you're the asshole."
We’re all so sorry that you can’t just do whatever you want while unleashing the externalities on society at large. You want to hack, go do it in your basement where you can’t affect the rest of us. You want to engineer, you have to answer to more people than just your mom asking what you want for dinner.
Well yes, that too. A mix of both, not sure of the percentages.
Frankly I wish there were a better place for the hackers to congregate without the capitalists. But whatever, at least the discussion here is civil and interesting. Best place I've found since Slashdot of old.
Waste brine is substantially more dense than regular seawater, so it tends to form a coherent layer that doesn't mix easily: it's why waste brine sinks to the sea-bed and spreads out in a layer.
The waste product is brine. It's an extremely salty sludge that's toxic to marine life. In the same way that fresh water is "just" diluted seawater, but pumping millions of gallons of it into a coastal ecosystem would wipe it out.
They provide some detailed and constructive thoughts. What exactly does your comment provide? Some sort of complaint which could be solved by yourself by not going into the comments or not reading theirs, hope this helps you in the future.
Brine discharge is an issue, but the geography of the North American West Coast is favorable for that. In most places the seafloor drops down fairly deep just a short distance offshore. Past about 400 ft / 120 m there is no flora at all, and most fauna is clustered around rock structures. So, the impact of brine discharge can be minimized with careful pipeline siting.
Careful pipeline siting indeed. The author needs to update the proposal to have the brine exiting on the Pacific coast, rather than annihilating the the Sea of Cortez.
Surely the massive open air pools of salt used for sea salt production have figured out how this process works.
On the Californian coast, there is already at least https://en.wikipedia.org/wiki/South_Bay_Salt_Works , a sea salt production facility that uses salt pools. They produce 80k tons annually of salt, which means they process 2666k tons of seawater to get that. If that one salt production facility used brine as their source instead of seawater, they would have allowed the facility to produce 2580k tons of freshwater. The "urban" usage of water in California is 10 million acre-feet (ish), so that's not exactly a significant amount.
Your naive solution just creates an even more gigantic stagnant stinky mess of a Salton "sea". The entire point is to reengineer the salton sea as a beautiful ecosystem and lake by diluting all the salt with 5MAF of RO desalinated water. The added benefit is huge economic revitalization of the entire area. Plus, because of the value of minerals in the brine, and the cost-effectiveness of solar power, it is not as expensive and crazy of an idea as one might think.
Take excess water from SE floods and pump it west opportunistically using excess renewables. Bonus because you can use the pumped water as gravity storage.
Yes, it is not cheap, energetically, to pump water. Yes, you have to cross a big mountain range(which increases opportunities for gravity storage).
For some reason, this suggestion always gets a lot of comments from folks living around the great lakes who think we're going to 'steal' 'their' water(just like they 'steal' CA grown produce, I guess?).
Anyway, a national water grid is needed for national food security and can mitigate flooding damage in the SE(probably more important b/c of AGW).
That report is mainly about the upper Mississipi (Midwest) not the lower, or points east (Southeast).
And it is only supposed to run during large scale flood events, which the report cites as lasting ~80 days, worst case? Looking at flood event frequency, this
report cites: 1912, 1913, 1927, 1937, 1965, 1973, 1982, 1993, and 2008.
So, let's be generous and double the event length to 160 days and double the event frequency to ~20 per century (increasing, to be sure). That's a time utilization of the infrastructure of ~9%, if Ima doing the math right.
It is apparently true: water runs uphill toward money. In this case, literally multiple miles of vertical elevation gain to get it to the Navajo Nation.
I mean I could see maybe pumping to Denver, or maybe over the continental divide past Denver, but... direct to almost the NM, AZ border?
Maybe just start with baby steps and for instance charge those good enterprising folk who farm alfalfa with nearly free water in the AZ desert and ship it to Saudi Arabia.
Seems to me like atmospheric water generators are a good fit here. That gets rid of the brine problem entirely, and from what I've read it's competitive in terms of energy consumption.
I've been thinking about this as well. As climate change affects the distribution of potable water on the planet, it would seem prudent to start installing solar backed desalination and water pipelines to ensure water security for areas at risk.
Now I'm no hydrologist, and haven't researched this idea deeply yet, so don't know second and third order effects (i.e. brine disposal mentioned above, and of course the economics of such a venture.) It seems at some point our collective hands may be forced and we may have to do something that doesn't make a profit, yet sustains humanity as a going concern.
Finally, the fact that we haven't "terraformed" in this fashion drought-stricken places like Africa or elsewhere is a pity. But yes, economics, profit, geopolitics, power struggles, I get it.
I wonder if this would be cheaper than just paying the water rightsholders not to use the water?
If the Salton Sea doesn't have a steady input (from snowpack? not familiar with it), doesn't desal mean we're really just expanding the unsustainable use of the Colorado, maybe delaying it another few decades, but ultimately still growing more and using more water than its watershed can naturally sustain -- especially as climate change increases?
I think the fundamental problem here isn't that we need to make more freshwater out of brine, but that the California (and other) water rights are set to levels that cannot realistically be maintained. The law needs to change even if that hurts the grandfathered rightsholders; there just isn't the same amount of water anymore.
Lots of questionable assumptions in this article, but I wanted to call this particular calculation out because it's so blatant:
5 MAF/year of 6% salinity brine contains more than 10 million tonnes
of magnesium, comparable to current global production, not to mention
other light metals. At spot prices around $5000/T, a mature brine
extraction industry could net >$50b/year
"Net" means after expenses, so this calculation is assuming that extracting 100% of the magnesium from the brine would have zero cost, not to mention that it also assumes that doubling the world supply of magnesium would have zero impact on its price.
The article claims that the plan described could produce 5MAF / year (the entire allocation of Colorado River water for California). There's no explanation I could find of where this water will come from. The Salton Sea itself only holds 1.5MAF.
The title also seems a bit grandiose. "The US Southwest" for most people I think extends at least as far as the I25 corridor up through NM and CO, and for some it might even reach into western TX. The plan described would really have very little impact on the overall water situation here, even if it did actually live up to its claim of effectively freeing up CA's Colorado allocation.
Just charge people for the natural resources of the country via taxes. Resource and land taxes solve basically every single problem in the current American economy yet people do not want to even think about doing it.
US taxes are already complicated, in large part due to the effort to build incentives and disincentives in the way that you describe. And yet the process to build the existing incentives is inescapably political, and for good reason: if you impose a significant change to taxation, there are winners and losers on day 1. Nobody likes to lose, especially if they feel they are doing nothing wrong.
For your specific idea, the red/blue political map shows you who will probably lose.
> yet people do not want to even think about doing it.
probably because placing a price on some things seems too transactional. Not saying you're wrong, though. Just saying that's why. The alternative is allowing more rapacious disregard for the aggregate negative effects on everyone as a whole.
You're right - air's also getting a little too polluted for my taste. Maybe if I could get a hold of some taxed air, I could breath easy! We could put the pollutants back into the untaxed air too!
The details might be a bit goofy, but this sort of large scale geoengineering project is going to be the only way that the SW is going to remain inhabitable.
The American southwest has a couple big things going for it -- unlimited sunshine and an extraordinary amount of empty land. You can combine these things to create huge amounts of electricity which can be used to irrigate new farm land, power mines and build new cities.
The status quo of drawing down on the increasingly precarious water supply is not feasible though. Before the unprecedented snowpack of 2022/2023, many regions were facing extreme water rationing.
Habitable? There is plenty of water for it to be habitable, residential use is a drop in the bucket compared with agricultural use. Without a technological solution, we'll have to scale back agriculture, but that's not a regional problem, since the market for food is an international one.
Also, we don't have to get all of the water from desalination. Southern California can use desalination, which makes sense to the ocean, short distances, and solar power. That frees up Colorado River water that Nevada and Arizona can use.
Desalination will probably never be worth it from agriculture, but agriculture should survive on the water they can access after people.
There's a whole lot of randomness in whether (or not) a submission "makes it" on HN. Re-submission cutoffs, crediting the first submitter, etc. would all require more rules & implementation. We pretty much don't care to bother.
So basically pump seawater up from the Gulf of California across the border over a flat floodplain to the Salton Sea (south of joshua tree) and use cheap PV to run desalination plants that will restore one of our biggest environmental disasters https://99percentinvisible.org/episode/sea-worth-salt back into a vacation hotspot greater than Palm Springs.
Costs of the PV and desal (relatively cheap but still absurdly expensive in absolute terms at this scale) will be offset by real estate development and hand-wavey mineral extraction from the sea water.
Environmental impacts of desal's salty waste stream is hand-waved away.
I mean, economic math miiight pencil out. But basing the speculative prosperity of an entire region on a bunch of water and energy machines seems... well... fragile? Full of hubris? Seems like a really expensive way of maintaining an otherwise-unsustainable Potemkin vacation village.
But then again, that's basically the story of the american southwest, so, /shrug? (see Cadillac Desert and all the water stories out there...)
AFAICT, restoring the Salton Sea and capturing the land appreciation is the mechanism for funding the project, not the goal. The goal is to restore the Colorado river.
And what pays for it again in a decade when the corroded water pipelines start to need replacement?
Or 30 years when the solar reaches end of life?
I assume original developers will have cashed out by then, someone else is left holding the bag, and the Salton Sea collapse story plays out a second time because it's just too expensive to maintain. That, or it's an exclusive enclave to the LA ultra-wealthy who don't mind that the high taxes keep the undesirables away, all while they've gotten the state to subsidize their vacation homes because the state is trapped and can't afford not to keep the machine running.
Not saying it doesn't work. Clearly it does, at least for a time or up to a certain level of population (Phoenix is banning new development because it's literally out of water, California is poster-child for water wars).
I guess it's something about spending that much effort and human capital to force something so inherently unsustainable that just seems... wasteful? Full of hubris? I don't know, maybe it's just a general sadness that this much ingenuity isn't being spent elsewhere where it could amplify existing natural forces instead of fighting a never-ending battle against entropy for something that doesn't want to exist.
Or maybe I'm just an internet sourpuss without enough vision. I just can't shake the "why are we doing this" melancholy about this.
Yeah it wouldn't be a city but just as a fun fact Las Vegas means "The Meadows" it had a really big aquifer and artesian springs fed by the Spring Mountains. It was sustainable as a town without the dam. Vegas also is allocated a very small portion of the water from Lake Mead, Nevada only gets about 4% of what is taken from it every year, and most of that is for farming still. The city probably needs like 1% to survive.
And then there's the problem of removing all that pesky lithium, 3400 kilotons, enough to support over 375 million electric vehicle batteries, which fortunately, is not very important towards reaching net-zero emissions by 2050. [0]
We desperately need to focus on conservation efforts instead of attempting to engineer "solutions" that only end up encouraging further consumption. Hot take: Maybe the American SouthWest wasn't meant to support > 1/3 of America's agricultural output. Solar desalination of the Salton traps humanity in an energy contract when we could achieve meaningful conservation efforts instantaneously by banning the production of many water-intensive luxury crops. Why is Arizona farming alfalfa for Saudi horses? Why is California producing 2.8 billion pounds of almonds a year? Why is the United States one of the highest consumers of red meat in the world when sustainable plant-based alternatives exist and use a fraction of the water? This regional water crisis (as well as our global climate crisis) cannot be solved without making bold sacrifices to our daily lives. I know this is Hacker News, but not everything can be solved with new/additional technology.
> We desperately need to focus on conservation efforts instead of attempting to engineer "solutions" that only end up encouraging further consumption.
"We desperately need to find ways to massively change human nature, rather than using our vast combined expertise to engineer solutions that let human nature work for us rather than against us."
Any solution to a systemic problem that can be articulated as "If people would just..." is doomed to fail. People will not just. People will continue finding ways to convert resources into better lives—for better and for worse.
Posting on articles like this saying "No! We can't keep finding ways to make consumption not harm the ecosystem! We have to force people to live austere, monk-like lifestyles! Only that will truly save us all!"
Like, I'm as frustrated by the idiocy of growing almonds in California as the next guy, but if this solution will actually work the way it claims to, then we may not need to worry about that anymore. And furthermore, it would mean significant improvements for various other parts of the world currently reliant on transporting enormous quantities of fresh water long distances to coastal areas.
This is Hacker News. Even if everything ultimately cannot be solved by technology, we sure as hell are going to give it our best try. That’s literally our most abundant resource here.
I’m not against using technology but my concern is that we need to treat resource consumption as a form of addiction. Humanity frequently uses technology as an excuse to further consume instead of using it to pay off ecological debt.
This is so dead-on it hurts. The "taming" of the rivers in the American west by the Army Corp of Engineers has been romanticized and the underlying motives have been swept under the rug: we prioritized these massive public works projects to provide cheap water to big ag businesses at the cost of sustainability and residential access.
IMO we should absolute not be exporting anything farmed with subsidized water while the survivability of just living in the US southwest is uncertain due to current water levels and climate patterns. That seems like the lowest of low-hanging fruit.
It is probably cheaper to do Solar PV due to unit economics rather than overall system efficiency. There's been a lot written on learning curves and wright's law, but rate of improvement is driven by design complexity and need for customization. Concentrating solar is both more complicated and needs more site customization, whereas solar pv modules are simpler and fly out of factories by the millions.
I'm going to go out on a limb and claim there's more than enough water for the people - the area is just unsuitable for the economic activity a small fraction of those people engages in. Move that.
I thought this would be a post from Rain Maker but it is another promising project altogether. If you’re interested check out Augusts Doricko’s company looking to do cloud seeding in the same region https://www.makerain.com/
I would really love to see the Los Angeles basin get its primary water needs met from desalination. This would lessen the need for the LA dept. of Water and Power taking water from the Owens Valley north of the LA area which subsequently turned the valley into a desert.
There's an abundance of freshwater in the east coast, northwest and midwest. Why not shift some of the exess water from the great lakes, east coast and northwest to southwest? Can't we pipeline the water to giant reservoirs in the sw or even carve extend tributaries from the missouri river or create canals down to the sw? It's not exactly rocket science.
Way, way too expensive. Pumping water east of the Rockies would use a ton power. Local desalination would cost way less. This plan is not feasible because it pumps water from Sea of Cortez to Salton Sea over 200 mi.
The author, who holds a PhD from Caltech, proposes taking advantage of the decreasing cost of solar power to enable a new age of clean water abundance in California, sustainably, with the potential for massive revenues and profits at all steps in the value chain. Even if the author's calculations are off by a factor of two, the proposal looks like it could work. At a minimum, it merits serious consideration. The status quo will not solve our pressing environmental problems.
The main challenge an innovative large-scale project like this one would face, I think, is a regulatory bureaucracy which to me often seems like it was designed for the technologies and infrastructure of the 20th century, not for those of the 21st century. I shudder to think of, say, inspectors who are highly trained on narrow technical matters, but who lack a fundamental, multi-disciplinary, big-picture view of the entire project, deciding whether to approve individual tiny little parts of it.