Wired has an article about John Piña Craven, who has a cunning set of plans that all involve exploiting temperature gradients between deep ocean water and the surface:
Craven hopes that within a year, bulldozers will begin clearing land on Saipan and engineers will start sinking a pipe to pump icy water from the ocean depths to produce electricity and freshwater. And back in Kona, Craven expects to use cold-water agriculture to transform five acres of otherwise barren lava fields into the world's most productive vineyard.The problem is, this reads just like a science fiction novel I read in the mid-1990s, and I can't remember the title! The novel was a mediocre attempt at an epic story, which begins with a mad scientist who converts an oil tanker to pull up cold water from a few hundred meters beneath the surface, and use the temperature gradients to drive electrical generators. The story unfolds in leaps and bounds, and at some point his granddaughter is a trawler captain who runs the company founded by the mad scientist, and the fleet of trawlers are bigger, have fatter pipes, pull more water from even deeper parts of the ocean.
I thought it may have been one of Damon Knight's later novels, but that doesn't appear to be the case.
