Thermoelectric power plants boil water to create steam, which then turns turbines to generate electricity. The heat needed to boil the water can come from burning fuel, nuclear reactions, or the sun. As the steam passes through a turbine, it must be cooled back to water before it can be used again to generate more electricity. Colder water cools the steam more effectively, increasing the efficiency of electrical energy generation.

Just as living organisms cannot survive without water, oil refineries and petrochemical plants cannot function without water. Water is used in water cooling systems, to provide steam and fire extinguishing systems. Petroleum products and fuels produced after distillation and various catalytic and cracking processes must be cooled. Water is the best fluid for this.