<P> Cooling towers originated in the 19th century through the development of condensers for use with the steam engine . Condensers use relatively cool water , via various means , to condense the steam coming out of the cylinders or turbines . This reduces the back pressure , which in turn reduces the steam consumption , and thus the fuel consumption , while at the same time increasing power and recycling boiler - water . However the condensers require an ample supply of cooling water , without which they are impractical . The consumption of cooling water by inland processing and power plants is estimated to reduce power availability for the majority of thermal power plants by 2040 -- 2069 . While water usage is not an issue with marine engines , it forms a significant limitation for many land - based systems . </P>
why does cooling water run through the condenser
to condense the steam coming out of the cylinders or turbines