Comment by londons_explore
1 day ago
I can assure you there is plenty of water. There are floods in lots of places every year. The oceans are full of water that for just 5kWh we can desalinate 250 gallons.
The problem is that the water and energy aren't where the users want it to be.
But pipes are relatively cheap - if humanity cared enough, we could build pipes to distribute the plentiful water everywhere.
But it turns out the people without much water tend to be in very poor places and warzones where there isn't much appetite for spending money on pipes.
Oh boy, lemme tell you: water management is one of those things that's More Difficult Than It Seems.
I'm going to recommend Cadillac Desert, which is by far the most entertaining and readable book on water. It goes into the history of water in the western US, a dry region that's very dependent on the Colorado River. The American West isn't a poor, war-torn area, and a LOT of money has been spent on various projects - but water is still a serious issue.
Things like "big pipelines to move water around" have been tried, but they're enormously expensive, and they don't really put as much of a dent in the problem as you'd imagine. Dams can store some excess water, but they cause problems of their own (which is why we don't build as many, and are getting rid of dams we don't need), and they're a bandaid at best. There's not a good solution to "how do we move a TON of water around", at least not now.
Indeed, it's easy to overestimate the capacity of a large tube and underestimate that of a small river.
I'd also add that it is easy to underestimate the water usage.
Desalination could be viable if it was only for subsistence/drinking. But water use is extensive in every single product/service we use and thing we cconsume. Cost of water going up across the board will have effects that shouldn't be underestimated.
The problem is not capacity of a tube. Let's take a recent example, Teheran. And let's assume desalination is just totally free. The city needs 1.2 billion m3 cubic meters of fresh water, and is on average 1200 meters above sea level. Let's not even count actually transporting that water, let's just discuss pumping it.
E = mgh, blabla, this requires 500 Megawatt constant power, 24/7/365, JUST to move the water up. This is the theoretical minimum power required to lift it against gravity. Does not include pumping the water inland.
This does not include actually pumping the water (ie. horizontal movement) (30% inefficiency would certainly not be considered bad engineering), doesn't include electrical inefficiency (30% in the power plant + 10% in the motors), doesn't include desalination (100%), doesn't include building the massive bridges something like this would require, doesn't include ...
So let's say you need a 4 Gigawatt power plant, every single drop just to keep this one city alive.
And for Asian cities, Teheran is tiny, about the size of Greater London or Paris. Most Pakistani cities are easily double that.
What needs to happen is that people in Asia need to abandon quite a few cities (yes, European cities are largely in, when it comes to water, sustainable places. Africa is less ideal, but still reasonable, US is reasonable with some exceptions, it's a bunch of Asian cities that are the problem here)
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Isn’t the problem ultimately that water is heavy and it takes a lot of power to pump it and that’s expensive?
You can pump water faster through a big tube but then you need big pumps and tons of electricity. If it’s going uphill that’s going to be serious power.
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What are your credentials on this topic? You speak with a lot of certainty, but fail to acknowledge any nuance that would complicate you world view, such that a lot of water shortages happen also in developed and peaceful regions (as it mentioned in the article). The people without much water are not only in very poor places and warzones, unless you are specifically referring to the people dying due to lack of water.
How would your proposed solution of "the oceans are full of water, just desalinate" affect affordability in agriculture and industry? I assume it would require vast investments in infrastructure that has not been built and is not even planned to be built, what would be required for such an infrastructure to be put in place and what challenges need to be overcome? Are there ecological concerns with the required scale of the operation (such as massive brine runoff at the coast)?
In short, you say "I can assure you there is plenty of water", but is that assurance coming from actual knowledge in the area at hand, or is it misplaced confidence due to dodging any inherent complexity before reaching your conclusion?
> What are your credentials on this topic?
OP has 38K karma; some people take it as a signal of valuable contributions to HN, other people understand it's signal of throwing everything at the wall hoping something sticks.
Hilariously, you got downvoted. Of course, HN is a popularity contest just like any other social media or social group for that matter.
Truth doesn't matter that much for most people, they just want to belong with a tribe even if they need to come up or agree with a lot of bullshit along the way. Thankfully there are people who don't care too much and they push the envelope.
A very efficient way to preserve large amounts of potable water for longer periods has traditionally been: glaciers in mountains. Climate change doesn't make water disappear but amplifies shortages as well as surplus. In many (previously) habitable parts of the world that change drives the price of water (and food mitigation) significant enough to render those areas uninhabitable. For example in Syria, Afghanistan and Iran this is a cause of poverty and conflict.
It's not just pipes.
Filtering (from bacteria, pollution, ...) is another issue, and it also affects floods (floods are not periodic, so you have to store water, but storing water for a long term is not always safe).
Even desalination costs are not trivial in all countries.
Let's say 1 kWh = 50 gallons. UN estimates talk about at least 50 gallons/day per person.
According to Wikipedia [1], the 2023 average electricity consumption in Burkina Faso was 0.14 MWh (=140 kWh) a year per person.
Then there's gravity. If your main source of water comes from the sea, you have to pull water from a lower altitude to a higher altitude, which means you are going against gravity, which means you need pumps. Other energy is required.
[1] https://en.wikipedia.org/wiki/List_of_countries_by_electrici...
> Let's say 1 kWh = 50 gallons. UN estimates talk about at least 50 gallons/day per person.
The energy cost of desalination is to convert sea water into freshwater. A person utilizes lots of water per day, but that water doesn't magically disappear, nor get turned back into sea water. Treating wastewater takes about 1 kwh per 1000 gallons, or about .05 kwh per person per day which is 13% of the per capita electricity consumption of Burkina Faso.
Desalination and long range transport are necessary only for what little is irrecoverably lost due to for example evaporation, and for offsetting the deficit from normal freshwater sources due to over-consumption.
I don't think UN is sounding the alarm of the planet running out of water all of a sudden, even they understand we have huge oceans that aren't going anywhere.
The report itself (https://collections.unu.edu/eserv/UNU:10445/Global_Water_Ban...) does actually talk about a lot of the background, why's and how we can start addressing it, in a very fleshed out form + an executive summary at page 13.
He's also not saying the world is running out of water or clean drinking water... etc.
> for just 5kWh we can desalinate 250 gallons … pipes are relatively cheap
I live 1500km from the ocean at 1500m altitude with 3 million other people in a place that’s neither poor nor a war zone.
Ignoring the cost of pipes for a minute (which is probably not small), googling the energy required to get 250 gallons (or about 1 cubic meter) of water from there to here, I get at least 140kWh [1], assuming a straight shot and no ups and downs along the way.
If that cubic meter is distributed to 5 households per day (so ~30kWh / household), which is less water than the average household uses [2] but might be reasonable for drinking water needs, we’d still probably be doubling the energy requirement for the entire region from ~30kWh per household [3] to ~60kWh. And the current ~30kWh usage is somewhat elastic and reducible, where the energy to pump water is not.
[1] (my calculation: large pipeline, 112MJ * 3<altitude> * 1.5<distance> ~= 140kWh) https://www.quora.com/How-much-energy-would-it-cost-to-pump-...
[2] https://en.wikipedia.org/wiki/Residential_water_use_in_the_U...
[3] https://www.eia.gov/energyexplained/use-of-energy/electricit...
A core piece of wisdom in chemical engineering is that anything is possible with sufficient energy. Fresh water being available in any particular part of the globe is the kind of classic thermal (read: energy) and mass transport problem that chemical engineering is all about.
Increasing energy production buys a lot of optionality when solving these kinds of physical world problems. It allows you to solve problems by throwing energy at them. It may not always be the most theoretically efficient solution, like throwing hardware at software performance problems, but it may be the only practical solution.
For this reason, it makes sense to build as much power generation capacity as possible even it isn't entirely clear what it will be used for. The inability of the developed world to massively scale power generation is the true environmental failure but people don't grok second-order effects.
There are also impediments to the economically rational allocation of water. Look at California for a prime example of this.
theres no drought in california.
if we wanted to tomorrow we could stop it.
its like complaining you are sweaty after working out
The "drought vs no drought" conversation hides the fact that a significant percentage of the water in the central valley aquifer has been pumped out for agriculture and other uses. Even if we stopped that tomorrow it would not recharge quickly, and the surface water is not sufficient for current demand.
Pedantically, you're correct. There's been drought in California for the previous 24 years, but this year there isn't one.
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> theres no drought in california.
CA is not in a drought right now. CA has been in conditions of persistent drought, with no more than a year or two of respite, for two decades. The last sustained period of sustained at-or-above-desired-level precipitation ended in 2007.
As always, Wikipedia explains this well: https://en.wikipedia.org/wiki/Droughts_in_California
Your logic amounts to "I'm not poor because I just got paid! Let's go to the bar tonight!"
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If you have references for these I would appreciate what you can find.
In general I believe abundance of resources exist in modern society and that there is less and less consideration for the lives of others, not in the "generational trauma" sense, but in the real basics of food, water and shelter.
A lot of people point to hard problems such as the "food miles problem"[1] but are, in many cases, conflicts that drive scarcity for one purpose or another.
[1]https://en.wikipedia.org/wiki/Food_miles
5-10 kWh per cubic meter pumped to Riyadh makes sense if you include the older process which requires oil to be burned to heat water first. Per capita, maybe Nicaragua can afford that. There are 65 countries poorer than Nicaragua.
The onion echoes your sentiments: https://theonion.com/report-every-place-on-earth-has-wrong-a...
They actually scooped the UN by over a year :)
It's as if they choose the word bankruptcy for a reason.
The problem is that while there is a lot of water available, more than our needs, we do not use water efficiently. In particular, food production is horribly wasteful with water. Even small farms will dump 100s of gallons of water per minute (yes minute) onto the ground to ultimately be washed away or evaporated.
What that means is that the piping to get enough water everywhere is enormous. The global usage was 2 quadrillion gallons of water. [1]
There are ways to use water much much more efficiently, but they are expensive to implement. Hydroponics can grow a lot of food, but it requires a lot of power and infrastructure to get setup.
[1] https://www.htt.io/learning-center/water-usage-in-the-agricu...
It's fun that desalination is always the first thing to pop up as an answer to that, and never water usage reduction
I assured you that water usage can be mismanaged even with plenty of pipes and water infrastructure.
Saudi Arabia has an incredible water piping system because they are rich. The poor cannot do that.
Saudi Arabia uses more than half of the petrol they extract on desalination.
It's not sustainable and once it runs out, the country will go back to being a poor desert.
One estimate focused specifically on oil burned for desalination puts Saudi Arabia at about 300,000 barrels per day used for desalination.
Separately, a reputable energy sector overview notes desalination is about 6% of Saudi Arabia’s electricity consumption (in 2020) [0] [1], which is nowhere near implying over half of extracted petroleum.
300,000 ÷ 9,500,000 ≈ 3.2% of crude production.
[0] https://www.ifri.org/en/studies/geopolitics-seawater-desalin...
[1] https://www.eia.gov/international/content/analysis/countries...
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There’s a big glowy thing in the sky that they can use to extract energy also. They have a lot of that energy too
Considering the target use case and location, they can very much replace the oil use with solar panels. It's actually perfect, because water usage is probably much lower at night, exactly when solar is weak.
I doubt they are going to go back to being poor that hard. They might not get as much easy money, but once the core infrastructure is built, it doesn't cost as much to maintain it.
Are you sure? That’s insane if true.
It genuinely puzzles me why they wouldn’t buy some solar panels to run desalination. The oil they’d then be able to sell instead of burning would pay for it easily.
Of course there is not always a good reason. The reason may be that the country is run by aristocrats who are rich and comfortable and don’t care and the present thing works so why fix it. If the system does stop working it’ll only really impact the poor.
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Same with food. Plenty of food, just not where its needed.
well for food, its that "where its needed" is somewhere really specific: Plenty of food, just not paid for.
> But it turns out the people without much water tend to be in very poor places
Hmm... I wonder why those places are poor.
> But pipes are relatively cheap - if humanity cared enough, we could build pipes to distribute the plentiful water everywhere.
Once you start moving water uphill, it becomes vastly more expensive. It takes a lot of power to move water uphill.
Sorry but you have not done the math on the energy costs too pump water from the ocean.
Why on earth is this the top post?
In other words: a crisis.
Yes 250 gallons can save a lot of people from dying of thirst but have you considered that with that same 5kwh we can also produce 1 tiktok ai slop video of the queen boxing with mike tyson?
Salt is engineers' kryotonite.