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There's also the problem of what to do with the high salinity waste water that is generated from the process. Simply dumping it back into the ocean can cause en

There's also the problem of what to do with the high salinity waste water that is generated from the process. Simply dumping it back into the ocean can cause environmental problems.

cpach 12y ago
What about putting the waste water in a salt pan?
refurb 12y ago
What problems would it cause? As long as you had decent mixing, you'd barely change the local salinity.
ptaipale 12y ago
I have a hard time understanding this would be a problem, considering the scale, i.e. how much water there is in an ocean. Let's say we take the amount of water mentioned in a link in another comment, and desalinate 54 million cubic feet of clean water per day in a single plant. That is 204 400 cubic meters per day. It is a huge amount, but we're talking about operating this plant at depth of 1 km. 204 400 cubic meters is 0.0002 cubic kilometers. The California Current flows at around 0.25 m/s which means that the cubic kilometer of water around the desalination plant will be completely exchanged almost once per hour, 21.6 times in a day. I would say that the salt that you take from desalinated water is an entirely insignificant problem when just left in the ocean, even locally. It's a drop in the ocean. Most likely the saltiness of water will vary a lot more due to other reasons (e.g. how much water evaporates locally). Other aspects of access to more water in places like California are probably a much more relevant environmental problem. That water is mostly going to be used as irrigation water in agriculture. This will flush a huge amount of earth particles to the ocean. Literally, it will eventually wash away the agricultural land, unless it is used sparingly. When doing that, it puts additional earth material in streams and rivers. And then there are the issues of fertilizers, pesticides etc for the ever increased volume of agricultural production.

There's also the problem of what to do with the high salinity waste water that is generated from the process. Simply dumping it back into the ocean can cause environmental problems.

cpach 12y ago

What about putting the waste water in a salt pan?

refurb 12y ago

What problems would it cause? As long as you had decent mixing, you'd barely change the local salinity.

ptaipale 12y ago

I have a hard time understanding this would be a problem, considering the scale, i.e. how much water there is in an ocean. Let's say we take the amount of water mentioned in a link in another comment, and desalinate 54 million cubic feet of clean water per day in a single plant. That is 204 400 cubic meters per day. It is a huge amount, but we're talking about operating this plant at depth of 1 km. 204 400 cubic meters is 0.0002 cubic kilometers. The California Current flows at around 0.25 m/s which means that the cubic kilometer of water around the desalination plant will be completely exchanged almost once per hour, 21.6 times in a day. I would say that the salt that you take from desalinated water is an entirely insignificant problem when just left in the ocean, even locally. It's a drop in the ocean. Most likely the saltiness of water will vary a lot more due to other reasons (e.g. how much water evaporates locally). Other aspects of access to more water in places like California are probably a much more relevant environmental problem. That water is mostly going to be used as irrigation water in agriculture. This will flush a huge amount of earth particles to the ocean. Literally, it will eventually wash away the agricultural land, unless it is used sparingly. When doing that, it puts additional earth material in streams and rivers. And then there are the issues of fertilizers, pesticides etc for the ever increased volume of agricultural production.