Classifying the different cooling systems of thermal power plants and knowing their respective water demands is fundamental when analyzing the water footprint in the energy sector. Therefore,
What are the cooling water demands of air-condensers?
Do they belong to open-loop system, wet-recirculating or closed-loop systems, or dry-cooling?
http://www.world-nuclear.org/information-library/current-and-future-generation/cooling-power-plants.aspx
The demand for cooling water depends on the required cooling load. And choosing an open or closed loop depends on the system configuration, but if you cant recover the heat that has been picked up by water, an open loop would be logical.
Cooling water demand is purely based on your cooling load as per your condenser design. Open or closed loop water system is based on your water quality means water treatment system was installed or not and also water availability.
You don't need to use cooling water if you are useing Air-cooled condenser...