> A possible product that I think is likely to play out this way is water desalination. Desalinated water is very expensive because of the embedded energy cost: it's often described as "bottled electricity". Currently we tend to use reverse osmosis because it's more energy efficient; but if you don't have to worry about energy costs, you might choose instead to boil water and distil it: since the capital costs are cheaper.

Here's another possibility: Bitcoin mining.

It's been discussed a lot - mostly hypothetically, but has a fraction of the distribution cost. There is a non-negligible capital cost that will turn over periodically. But there's nothing to ship at the end of it all. And if you're getting paid to use power, then it might be possible to come out ahead.

And then there's the non-negligible cost of locating a desalination plant next to the ocean, where the effluent pollutes the environment.