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If you built a desalination system say… 500 feet under the ocean and have the pressure above pushing water through the filters, is it possible to lower the amount of required energy just a little? Then you’re more pumping water out of the system than pumping it through heavy filters
And now you need to pump the final product up to the land surface, adding cost there as well.
I was surprised how cheap it is. Desalinated water costs ~50 cents per 1000 liters [1]. That's about the same amount of water as a typical American household uses per day. 50 cents per day for a fully desalinated water supply is... incredibly cheap. If you're interested in water policy and water management / engineering, I cannot recommend enough reading the book "Let There Be Water: Israel's Solution for a Water-Sta…
*typical American household uses directly. Don't forget food, industrial, etc
https://ourworldindata.org/grapher/water-withdrawals-per-cap...
So that is around $775 per person per year assuming no net change in water use. In contrast, Germany uses around 410 m^3, France around 475 m^3, and Australia around 724 m^3, so the US is a significant outlier.
Earlier quoted context omitted.
*typical American household uses directly. Don't forget food, industrial, etc
Yes, but you pay for that when you purchase the products. These costs are baked in.
Earlier quoted context omitted.
>In 2022, 85% of the country's drinkable water was produced through desalination of saltwater and brackish water. Israel does this by burning massive quantities of fossil fuels: https://en.wikipedia.org/wiki/Energy_in_Israel#/media/File:E... It's not even remotely economical without huge government subsidies. Completely untenable with current technology for poorer countries, or anyone that cares at all about carbon e…
> It's not even remotely economical without huge government subsidies. Why shouldn't drinking water of all things receive subsidies? Why must drinking water be a for-profit enterprise?
It's about sustainability, not profit. Of course wealthy nations can (literally) burn enough money turning fossil fuels into water to make their population comfortable and happy. But most can't, and the externalized cost is unimaginable at a global scale.
Is it just me, or did this article dance around the question? I am not a physicist but let me give it a stab: except for a few specialized steps like UV or oxidizing heavy metals, most filtration is mechanical. A series of filters with smaller and smaller pores capture more and more of the mess in the water like bacteria and particulates while UV breaks down viruses, the oxidizer precipitates out metals, and so on. N…
It takes less energy but produces a concentrated liquid waste stream that must be disposed of. I've heard that this brine is toxic. Does this make disposal an issue? Is the toxicity true or hyperbole? I mean, do we know how bad it is, and if we can do anything safely with it? It seems like "salt" is useful in a lot of contexts, including industrial, so can we do something with the brine besides disposing it somewhere…
Earlier quoted context omitted.
*typical American household uses directly. Don't forget food, industrial, etc
Yes, but you pay for that when you purchase the products. These costs are baked in.
Earlier quoted context omitted.
Exactly, desalination is very popular in arid countries. With renewable prices trending down, it's getting cheaper too. Basically, don't use consumer grid prices because those still include a fat profit margin for the energy suppliers and their sunk investment in legacy expensive generation using gas, coal, or nuclear. If you are within 40 degrees of the equator, which is where you'd find most arid places, solar is a…
Focusing on the financial side is okay, though I would mention that the energy cost is only half of the total cost, according to the literature. But desalination is not only about money. It has an impact on its environment, because it pumps fresh sea water and reject brine. These operations have a high cost for the local marine life. A large desalination plant means large patches in the sea where life is not sustaina…
If you built a desalination system say… 500 feet under the ocean and have the pressure above pushing water through the filters, is it possible to lower the amount of required energy just a little? Then you’re more pumping water out of the system than pumping it through heavy filters
Is it just me, or did this article dance around the question? I am not a physicist but let me give it a stab: except for a few specialized steps like UV or oxidizing heavy metals, most filtration is mechanical. A series of filters with smaller and smaller pores capture more and more of the mess in the water like bacteria and particulates while UV breaks down viruses, the oxidizer precipitates out metals, and so on. N…
It takes less energy but produces a concentrated liquid waste stream that must be disposed of. I've heard that this brine is toxic. Does this make disposal an issue? Is the toxicity true or hyperbole? I mean, do we know how bad it is, and if we can do anything safely with it? It seems like "salt" is useful in a lot of contexts, including industrial, so can we do something with the brine besides disposing it somewhere…
Too much salt can kill stuff (e.g. people, plants), so I suppose that makes it "toxic." Maybe there's a tiny amount old industrial pollution from anywhere an everywhere that concentrated in there, too.
However, if you're desalinating seawater, what's the problem with just dumping the brine back in the sea? Unless you introduced new stuff into it during the desalination process, you wouldn't be making anything worse.
Earlier quoted context omitted.
*typical American household uses directly. Don't forget food, industrial, etc
Freshwater withdrawals per capita in the US (which includes agricultural exports and animal feed such as alfalfa sent to Saudi Arabia) are around 1550 cubic meters per year. https://ourworldindata.org/grapher/water-withdrawals-per-cap... So that is around $775 per person per year assuming no net change in water use. In contrast, Germany uses around 410 m^3, France around 475 m^3, and Australia around 724 m^3, so the…
Freshwater withdrawals is a very broad category, it also includes water released to turn hydropower turbines. But it's also unfair to compare across countries without taking into account water sent between countries in the form of produce and products.