Structures designed to dissipate heat from the cooling circuit to the atmosphere. In order to maximize the energy conversion, the steam has to be condensed when exiting the steam turbine. This is done by a special cooling circuit; usually the tertial. There are two basic types of cooling towers. A forced draft tower uses fans to blow air through the sprayed water, which is cooled by evaporation. Natural draft towers have the shape of a rotating hyperboloid and are pre-stressed concrete structures up to 100 metres high. Air is naturally drawn in at the base of the tower. The water is sprayed at one fifth of the tower height and falls into a pool below the tower when it cools down.

In places where natural conditions permit, cooling towers are not needed and the plant is cooled directly by water from the sea or river.