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This works for domestic usage - not agriculture - and might be a good use for the huge amount of excess solar capacity were likely to have soon, but it’s expens

by acdha 2y ago

This works for domestic usage - not agriculture - and might be a good use for the huge amount of excess solar capacity were likely to have soon, but it’s expensive and NIMBYs are not going to want salt and other waste building up in their neighborhoods. It seems inevitable that they’ll have some capacity but I doubt it’ll ever reach the level where conservation measures relative to 20th century usage levels won’t be necessary.

trollbridge 2y ago
The salt goes back out into the ocean, which is rather large. Desalination is practical when paired with nuclear power (there is a possibility for even things like directly using the heat from nuclear to desalinate without converting to electricity and then back to heat first). But California seems dead-set on shuttering any nuclear plants and using imported power made with fossil fuels in other states instead. My in laws have to deal with rolling blackouts during very hot days at dusk. Perhaps after telling town residents not to flush toilets, take showers, or order tap water in restaurants, we can next just say to use no electricity at all. Might as well go back to the Stone Age.
- acdha 2y ago
  > The salt goes back out into the ocean, which is rather large. Yes, but that’s like saying it doesn’t matter if you get shot because the volume of the room is still less than 1ppb lead. You need to plan for how to avoid massive ecological disruption in the local area, which is possible but adds to the expense and gives NIMBYs another opportunity to delay or block things. These are classic economic problems: when something else is subsidized low, it’s hard for a competitor which doesn’t share those benefits to get established even if everyone would be better off in the long-term. Nuclear is a distraction - you don’t need such expensive power for this, or even the near-free solar California’s renewable focus will produce at many times. Researchers have been developing passive solar systems which use solar power directly and are suitable for deployment in places which don’t have enormous supplies of cheap electricity.
  - trollbridge 2y ago
    It's true that environmental impact matters (although the amount of salt we're talking about is negligible - it's hard to wrap your mind around just how big the ocean is vs. the amount of water being extracted from it). Desalination plants have been run for a long time in Israel and Saudi Arabia. To give you an idea of the scale involved, one of Israel's large desalination plants produced 332 acre-feet of water per day. The Red Sea is around 1.8 * 10^11 acre feet of water, so assuming the Red Sea never got replenished, that would take... 1.5 million years to empty it out. The plant is removing about 1,300 tons of salt per day, which may sound like a lot, but consider that the ocean currently has about 5.0 * 10^16 of salt in it, it's not significant, assuming they were discharging the salt to the ocean - which they don't! The output of a desalination plant is more brine produced than freshwater produced, so it's not at a very large concentration and the impact on sea life is minimal. Nuclear isn't a distraction because nuclear was already installed, was working, and is sustainable. Researchers are working on a lot of things, but research doesn't equal something that can actually meet demand for water today. Desalination works today and people rely on it for water around the globe. This would be a great improvement over trying to empty out Lake Mead and the Colorado.
jfoster 2y ago
What makes it expensive if the solar capacity is in excess?
- acdha 2y ago
  It’s a separate facility which has to be approved, built, and operated beyond the existing water supply infrastructure. It’s not unworkable but you have the problem that everyone’s water bill goes up compared to what they’re paying now, and that leads to political consequences, which is why everyone has kicked it down the proverbial road hoping that it’ll either get cheaper or the supply problems will become bad enough that nobody questions the need.

by acdha 2y ago

trollbridge 2y ago

The salt goes back out into the ocean, which is rather large. Desalination is practical when paired with nuclear power (there is a possibility for even things like directly using the heat from nuclear to desalinate without converting to electricity and then back to heat first). But California seems dead-set on shuttering any nuclear plants and using imported power made with fossil fuels in other states instead. My in laws have to deal with rolling blackouts during very hot days at dusk. Perhaps after telling town residents not to flush toilets, take showers, or order tap water in restaurants, we can next just say to use no electricity at all. Might as well go back to the Stone Age.

acdha 2y ago
> The salt goes back out into the ocean, which is rather large. Yes, but that’s like saying it doesn’t matter if you get shot because the volume of the room is still less than 1ppb lead. You need to plan for how to avoid massive ecological disruption in the local area, which is possible but adds to the expense and gives NIMBYs another opportunity to delay or block things. These are classic economic problems: when something else is subsidized low, it’s hard for a competitor which doesn’t share those benefits to get established even if everyone would be better off in the long-term. Nuclear is a distraction - you don’t need such expensive power for this, or even the near-free solar California’s renewable focus will produce at many times. Researchers have been developing passive solar systems which use solar power directly and are suitable for deployment in places which don’t have enormous supplies of cheap electricity.
- trollbridge 2y ago
  It's true that environmental impact matters (although the amount of salt we're talking about is negligible - it's hard to wrap your mind around just how big the ocean is vs. the amount of water being extracted from it). Desalination plants have been run for a long time in Israel and Saudi Arabia. To give you an idea of the scale involved, one of Israel's large desalination plants produced 332 acre-feet of water per day. The Red Sea is around 1.8 * 10^11 acre feet of water, so assuming the Red Sea never got replenished, that would take... 1.5 million years to empty it out. The plant is removing about 1,300 tons of salt per day, which may sound like a lot, but consider that the ocean currently has about 5.0 * 10^16 of salt in it, it's not significant, assuming they were discharging the salt to the ocean - which they don't! The output of a desalination plant is more brine produced than freshwater produced, so it's not at a very large concentration and the impact on sea life is minimal. Nuclear isn't a distraction because nuclear was already installed, was working, and is sustainable. Researchers are working on a lot of things, but research doesn't equal something that can actually meet demand for water today. Desalination works today and people rely on it for water around the globe. This would be a great improvement over trying to empty out Lake Mead and the Colorado.

jfoster 2y ago

What makes it expensive if the solar capacity is in excess?

acdha 2y ago
It’s a separate facility which has to be approved, built, and operated beyond the existing water supply infrastructure. It’s not unworkable but you have the problem that everyone’s water bill goes up compared to what they’re paying now, and that leads to political consequences, which is why everyone has kicked it down the proverbial road hoping that it’ll either get cheaper or the supply problems will become bad enough that nobody questions the need.