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"Turning sea water into clean, drinkable water costs $2 to $5 for 1000 gallons. Less than half a penny per gallon is obviously absurdly cheap." - Elon Musk, 2023-05-07 https://twitter.com/elonmusk/status/1655262008898383872?ref_...
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In other words, you want to salt the land? Isn't that what marauders do when they want to destroy an area permanently?
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> The Sonoran Desert encompasses 120,000 square miles of southwestern Arizona, southeastern California, and in Mexico, northwestern Sonora and most of the Baja Peninsula. With nearly 3500 species of plants, 500 species of birds, and 1,000 species of bees, the Sonoran is the most biodiverse desert on earth.
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In 2022, 85% of the country's drinkable water was produced through desalination of saltwater and brackish water. If there is a real need, and a will to address it, we have everything we need to to it. https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in...
>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…
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
Probably very dumb idea, but would it be feasible to just pump and sprinkle sea-water on hot, dry desert and let it naturally evaporate, and then collect it as fresh rainwater back? i.e. how much water would you need to evaporate to have a noticeable increase in rainfall?
There is talk about pumping sea water into the Saharan desert in certain parts, which gets at that. https://www.youtube.com/watch?v=V2b7ztWvFOg
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A desert is a living ecosystem. Evaporating salt water would leave behind substantial salt solids. Think Great Salt Lake.
I mean, that's actually not too much of a downside, since salt is a fairly valuable economic good - Indian salt farmers do exactly that to harvest the salt crystals.
The energy costs are a bit of a red herring depending on local conditions. In California we currently "curtail" i.e. discard a huge amount of renewable energy in the spring season. If we can seasonally apply that energy to desalination, and store the fresh water for later, it is essentially a huge time-shifting battery that stores excess spring energy for the summer.
There's lots to unpack here why this isn't workable at scale. 1) Renewable energy product still has a cost associated with it, even if it is at times, excess. 2) That excess capacity, and the times when there's more energy produced than consumed might not match with water demand. 3) There definitely isn't, and won't be, enough excess renewable capacity to distill even a fraction of the fresh water consumed. 4) This m…
This cost is already paid for in the infrastructure. You're not going to tear down extra solar panels when demand is low just to reinstall them an hour later.
> 2) That excess capacity, and the times when there's more energy produced than consumed might not match with water demand.
Water can be stored very easily in large quantities and over long periods of time. Replenishing an aquifer in the summer will still help you even when the dry season is winter.
> 3) There definitely isn't, and won't be, enough excess renewable capacity to distill even a fraction of the fresh water consumed.
You don't need to distill 100% of freshwater, you just need to make up the difference between what is naturally available and what is used. The difference is generally small, especially when combined with water conservation methods. California's water shortfall could be covered by using just 6% of it's current annualized electricity generating capacity for desalination.
> 4) This means that you still have to calculate a per kWh cost for the energy consumed to distill salt water to fresh water. The average kWh might not be the same as the market average kWh price, since if you make your distillation plants oversized so you can utilize any spare energy production, but there will still be a price.
You would presumably locate your desalination plant in an appropriate location and operate it at appropriate times such that your cost per kwh is substantially below normal market rate.
> 5) This price will most likely mean that the per gallon cost of distilled water will be higher than RO, or water pumped through a pipeline.
RO would be desalination. A pipeline is still taking water from somewhere else, the price depending heavily on where you're getting it from and the geography between you and the source. In many cases there isn't a suitable freshwater source to pull from. Certainly there are no fresh water sources so limitless and readily accessible as the world's oceans.
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No. Unless you want salt-caked hair. And body. Curious, have you ever been to a beach?
yeah but I usually feel quite refreshed after coming out of the waves, but keep in mind we don’t need clean feelings to survive, we do need fresh drinking water
Earlier quoted context omitted.
In 2022, 85% of the country's drinkable water was produced through desalination of saltwater and brackish water. If there is a real need, and a will to address it, we have everything we need to to it. https://en.wikipedia.org/wiki/Water_supply_and_sanitation_in...
>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…
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…
But, why not really-long-pipe-with-small-holes-along-the-length? That seems to me like a simple mechanism to send the brine back into the ocean without causing a local disaster on the sea floor. Is there maintenance required that makes it more expensive than I realize?