And further, couldn’t they be used to power turbines as well through steam power?
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It could. It’s just that desalination plants are expensive and energy intensive and seen as measures of last resort as a result.
Scale.
Droughts happen because enormous areas of land lack water. If a hundred million acres need an extra inch of rain, that’s…well, way too much water. In addition, the enormous amount of salt produced by such stations would need to go somewhere, and dumping it back into the oceans would turn them into the Dead Sea before too long.
In addition, desalination is an incredibly energy intense process. You either need to evaporate the water (which, considering the properties of water, is absurdly expensive on that scale), or force it through osmotic filters which cannot be made on that scale using anything like our current infrastructure. I haven’t done the math, but I’m pretty sure even extracting all the energy of a nuclear weapon as heat and using it to boil water with maximum efficiency wouldn’t be enough to do anything like solve a drought.
If we tiled a couple deserts with solar power stations we could probably power such an operation. But at that point we have enough energy to do basically anything else we want to as well.
Desalination could absolutely be an option to meet urban and residential needs. Depending on water management in wet and dry years, urban and residential water usage only accounts for 8-11pct of the total state water usage. The remaining ~90pct goes to agricultural (Farming and Livestock) and environmental (Delta outflow, instream flows, and managed wetlands, etc) usage.
The problem with desalination is not so much the cost, although it typically costs 50pct -100pct more than ground water sources. The bigger issue is with Boron. Boron is difficult to remove from brackish water/seawater and in high concentrations it is toxic to plants when it accumulates in top soil. This makes desalinated water generally unsuitable for irrigation. It *can* be removed from water and there is a lot of research into various mechanisms to do so, but it adds additional cost and these processes don’t exist at the scale to meet agricultural demands.
Part of the problem of scale is what farming is used for. A huge chunk is used for livestock. Reduce the consumption of meat, you make a big difference in farming water needs
Not only are desalination plants expensive to build and maintain (salt is really corrosive), but even multiple plants wouldn’t ultimately meet the full needs of California’s extensive farming communities, not to mention the major metropolitan areas. Pretty much, there are too many humans growing too many plants and using too much water and energy which isn’t naturally available to that region even without drought conditions – Los Angeles has been getting water piped in from the Colorado river since the early 20th century.
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