Perspective on use of fresh water for cooling systems of thermoelectric powerplants in Florida
Cooling ponds, evaporative cooling towers, and once-through cooling systems of thermoelectric powerplants consume appreciable quantities of water. In Florida a cooling pond for a 1,000 megawatt nuclear power-plant operating at full load in sulluner consumes about 12.5 million gallons of water per day (0.55 cubic metres per second). A cooling tower for a plant of the same size consumes about 14.8 million gallons per day (0.65 cubic metres per second). Because the natural water loss to evaporation is greater for a water body than for a land area of comparable size in the same general environment, the total water consumption attributable to powerplant cooling may be greater for a cooling pond than for a cooling tower in instances where, for lack of a suitable natural water body, a cooling pond is created out of a dryland area. Additional water is required to maintain the chemical quality of the recycled cooling water, the quantity varying with the chemical quality of the makeup water and the concentration of chemical constituents that can be tolerated in the cooling water. Once-through cooling systems require 5 to 10 percent less water than cooling ponds, but the total withdrawal of water for this method is so large that it is practicable in Florida only along the coast where saline water can be used.
In 1970 cooling systems of powerplants in Florida consumed about 106 million gallons per day (4.6 cubic metres per second), mostly saline water. Water consumption for power production in Florida could increase to 400 million gallons per day (17.5 cubic metres per second) by 1990 and to 800 million gallons per day (35.0 cubic metres per second) by 2000. Demand also will increase greatly for other uses that require Fresh water. The continued use of saline water for cooling systems of 3owerplants would help to conserve the fresh-water supply for these uses.