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Exactly, desalination is very popular in arid countries. With renewable prices trending down, it's getting cheaper too. Basically, don't use consumer grid price

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 very good option for generating lots of energy cheaply. Cents per kwh basically, possibly dipping below 1 cent per kwh in the not so distant future. And since you can store water in reservoirs, it's OK to not be desalinating 24x7. A thousand liters takes about 3kwh. It's not really that expensive. If you run a very inefficient house in the US, that's actually what you'd need per day. You might consider some cost/water saving solutions if that worries you. But, either way, we're talking cents per day per household basically. Not nothing. But cheap enough that it is a common solution to get water in places that have average incomes far below those common in places like the US where desalination is mostly science fiction.

idoubtit 3y ago
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 sustainable. BTW, if an average US house really needs 1m^3 per day, that's appalling. These past years, my house has used less than 10m^3 per year and per person. 30× less. I'm afraid most US homes will keep wasting drinkable water and pressure society on building desalination plants, rather than halve (at least!) their water usage and protect the environment.
- jillesvangurp 3y ago
  True in shallow waters, a literal drop in the ocean if you pump the salty water a bit further out where it is deeper. The Pacific coast in the US is pretty deep even close to the coast. The Atlantic is pretty deep as well. Of course pumps and pipes cost a bit extra so there is a tendency to cut corners there. But it's not a challenging problem technically.

idoubtit 3y ago

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 sustainable. BTW, if an average US house really needs 1m^3 per day, that's appalling. These past years, my house has used less than 10m^3 per year and per person. 30× less. I'm afraid most US homes will keep wasting drinkable water and pressure society on building desalination plants, rather than halve (at least!) their water usage and protect the environment.

jillesvangurp 3y ago
True in shallow waters, a literal drop in the ocean if you pump the salty water a bit further out where it is deeper. The Pacific coast in the US is pretty deep even close to the coast. The Atlantic is pretty deep as well. Of course pumps and pipes cost a bit extra so there is a tendency to cut corners there. But it's not a challenging problem technically.