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7. Cheap Desalination

I keep reading stories for the past 10 years, every six months or so that this one has been solved.
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currently desalinized water makes for expensive municipal water. Costs for this are all over the map depending on where in the world you are from $600@acre foot to $2000@ acre foot.

By cheap desalination they mean desalination cheap enough for agriculture. Agricultural water needs to be under $100@ acre foot for expensive crops and under $50@acre foot delivered for less expensive crops.

Since most of the world’s deserts are within 1000 miles of a seacoast—if you kill the cost of energy so that pumping water is cheap and desalinizing water is cheap—then it becomes possible to turn the world’s deserts green and basically double the size of the habitable earth.

For cheap energy — Thorium lftr reactors are a good candidate.

There are two other big costs with desalination plants. That’s capital and maintenance costs. At the heart of both are RO membranes. There may well be a solution coming in the near future with graphene — which if it holds to its current promise will be as big as plastics were in the 1960’s or nylon or synthetic rubber in the 1930’s and 40’s. We’ll know in another 5 years.

Also it bears mentioning that salt needs to converted from a cost center to a profit center.

In practice cheap desalinized water would increase the habitable size of the USA by about 1/3-1/2, triple the habitable size of Mexico and increase the habitable size of Australia by a factor of about 100...and so on.

The world’s food issues would be resolved for as much as 300 years.