Thermal power generation

This industrial sector, which includes both conventional and nuclear power generating plants, withdrew 64% of the total water intake in 1996. Next to fuels, water is the most important resource used in large-scale thermal power production. Production of one kilowatt-hour of electricity requires 140 litres of water for fossil fuel plants and 205 litres for nuclear power plants. Some of the water is converted to the steam which drives the generator producing the electricity. Most of the water, however, is used for condenser cooling.

Why is so much cooling necessary? Because today's processes can only convert 40% of the fuel's energy into usable electricity. The rest is wasted. This shows the double cost of inefficient energy use: first, in the wasted energy, and then in the water required to cool the wasted heat to the temperature where it can be released safely into the environment. This requires a continuous flow of cooling water circulating through the condenser. All the cooling water is therefore returned to the environment much warmer. However, the temperature can be reduced using cooling towers and other such devices.

See also: Industrial Water Use Survey 

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