I poked around and the Carlsbad Desalination Plant wikipedia page has numbers. https://en.wikipedia.org/wiki/Claude_%22Bud%22_Lewis_Carlsbad_Desalination_Plant

I poked around and the Carlsbad Desalination Plant wikipedia page has numbers. https://en.wikipedia.org/wiki/Claude_%22Bud%22_Lewis_Carlsbad_Desalination_Plant https://en.wikipedia.org/wiki/Claude_%22Bud%22_Lewis_Carlsba... Cost about $1b to built. Energy costs are $49-5m a year. Total cost $108 million. That's inline with my rough memory that 45% of the cost is capital, 45% energy, and 10% maintenance. Fudge those numbers as you will. When I think about the economics it seems complex. Cheap power offsets extra capacity somewhat. Someone that actually manages, designs, plants probably knows real numbers.