Thermoelectric Power Plants
Approximately 89%–90% of electrical generating capacity in the United States is produced by thermoelectric power plants. These plants require freshwater for producing
steam in the boiler, for cooling and condensing the steam after it is used to power turbines and generate electricity, and for scrubbing flue gas of potential air
pollutants. The largest use of water at power plants is for cooling. The U.S. Geological Survey estimates that approximately 195 billion gallons of water is used
every day to cool power equipment. However, it is important to note that not all the water required for cooling is actually consumed (permanently lost). A large
percentage (about 96% on average) is returned, or discharged, to surface water supplies such as lakes and rivers and thus becomes available for other uses.
While only a small percentage of the water used to cool thermoelectric power plants is actually consumed, very large volumes are required
for use. Water permits are required to withdraw large volumes of water from surface and groundwater sources, and as competition for water
supplies increases, it may be difficult or impossible to acquire new water permits. In some cases, the costs of acquiring an alternative
water source can be less than freshwater, depending on quality and location. As competition for a limited resource increases, alterative
water resources will likely become more economically viable.
There are benefits and drawbacks associated with using alternative water sources instead of freshwater, but the overall considerations need to be assessed on a case-by-case basis.
