Fresh water,energy, and food from the sea and the sun

Surface waters of tropic and sub-tropic seas hold most of the solar energy retained by the earth; but the heat therein may be increased even more by heat which can be added by intensive solar heaters. The sea water so heated naturally or additionally by the sun, when flash evaporated, gives vapors which may be passed through a heat engine to give power, then condensed at a lower pressure to give fresh water, which may be much more valuable than the power produced. Heat of condensation is removed by circulating cold sea water from a depth of a few thousand feet. This water from the deep also has considerable nutrients for sea plants and animals coming from the degradation of former sea life; and these nutrients may be used in well studied mariculture systems to grow commercial food fish in ponds adjacent the land-based plant. Various arrangements of flows of the several liquid streams are presented to illustrate variations to the process which will produce fresh water and/or electric power, also food fish. These modifications may be optimized with various component systems, some of which are well known and evaluated in this usage, including the use of a second thermodynamic fluid, conventional multistage flash evaporation, also two of its variations: Controlled Flash Evaporation and Vapor Reheat. Calculations indicate that even without the use of intensive solar heaters, a profitable desalination and mariculture operation may be expected which would pay for its substantial cost in two or three years of profits; however, the incorporation of certain intensive solar heaters may increase the profitability significantly.