why isn’t ocean water filtered and used when somewhere is having a water crisis?
In: 144
Because desalination is a costly and lengthy process. Digging for groundwater is much more manageable, and in short term- bottled water is a good way to avoid people getting sick or dehydrating
Removing salt from water requires a ton of energy. There is almost always a different option that requires far less resources than desalination.
Short answer: it’s extremely difficult and extremely expensive for not a whole lot of payout in terms of the amount of drinkable water you get x resources used.
*Edit* Also transporting it uses a lot of extra resources
Wells are more efficient.
The places that use desalination all have money and energy to burn on the process. It is pretty expensive to maintain a desalination plant. The process to desalinate relies on levels of filtering way beyond what we normally think of for filtered water because salt can get through a normal filtration system that is operating on a large scale. Even in California where water shortages are many, it has been slow going to construct the ones they have, and then you have to send that water against gravity to get it to places that need it. It’s pretty expensive and so is slow to come into the market. That being said, the technology IS being used in many places , which means innovation will continue to happen and maybe some day soon the scale will tip toward “affordable enough” to be tried in poorer areas that suffer from water crises.
De-salination requires a LOT of energy. Places that are experiencing a water-crisis are also likely to be experiencing an energy-crisis (post-natural-disaster), which makes it a double-whammy.
However, it is a practical solution when energy is not a limiting factor – the Saudis do this since they experience extreme water scarcity but have plenty of oil to supply the energy
[https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in_Saudi_Arabia#Desalination](https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in_Saudi_Arabia#Desalination)
There are a few ways to do it, but the most common way to desalinate seawater is with Reverse Osmosis. This involves pushing seawater through a series of filters and membranes that separate it into pure water and a salty concentrated brine. This process is very energy intensive because you have to highly pressurize the water to push it through the membranes.
There has been some effort building these in places with minimal fresh water and cheap available energy like Saudi Arabia. but it is an issue of scale.
There’s a ton of research in this field because it would solve a lot of water crises. A lot of islands and coastlines suffer from salty groundwater which makes it hard to grow food. Finding a way to desalinate water in a profitable way would be a game changer for a lot of people. [this](https://youtu.be/ke5jUHe4fII)might interest you
It is.
Half our state’s water comes from desalination and our state is over three times bigger than Texas.
As others have emphasized, it is an energy problem. And thus a cost problem. The technology is there and is very well understood, it is currently simply too expensive to run economically. The reason is that the types of filtration membranes used for desalination require a lot of pressure to push the water through, which raises the cost.
Whoever invents an energy-cheap desalination process might actually make trillions.
Source; am a water filtration scientist.
I live in Perth Western Australia. We get 45% of our water from desalination. It is powered by a wind farm.
[https://www.watercorporation.com.au/Our-water/Desalination](https://www.watercorporation.com.au/Our-water/Desalination)
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