Unveiled here is the most feasible form of power production for independent city states floating on the oceans. It provides not only power but fresh water, air conditioning, and nutrient rich ocean water for aquatic farming.
I am talking about a machine that, once built, provides all of the above for free except for maintenance costs. But there are caveats and limitations.
It is a simple device that takes full advantage of the elements existing on the ocean. Nearly 90% of the oceans’ water is classified as “cold ocean water”. It is at temperatures of between 32 and 46 degrees Fahrenheit. The tropical regions of Earth have a mean temperature of 64 degrees F. This is a temperature differential that can be exploited, but only in those regions that are warm enough to produce a significant differential. Happily, this can take place in the tropical and most subtropical environments, about 30-40% of the worlds surface area.
Here is how it works: Cold ocean water is pumped into an elevated heat exchanger at the top of a cylindrical tower. Moisture bearing wind is directed through this heat exchanger and down the center of this tower. Fresh water condenses on the heat exchanger and is collected. The now cooled air falls faster and faster to a turbine at the bottom of the tower where that energy is captured by a wind turbine, producing electricity. Electricity is also produced by cold ocean water coming back down from the heat exchanger and the fresh water coming down from its collection tank near the heat exchanger. The cooler, drier air that comes from the outlet of the air turbine can be used for refrigeration or air conditioning. The still cool ocean water from the heat exchanger is full of nutrients that have been locked into it at ocean depths. This can be used for farming fish, crustaceans, and seaweed.
Included here are some images showing what this device might look like and descriptive labels of some of the parts: