Power generation facilities that rely on thermal sources as their energy inputs such as Coal, Natural Gas, Geothermal, Concentrates Solar Power, and Nuclear require cooling technologies to reject the heat that is created. The second law of thermodynamics states:
"No process can convert heat absorbed from a reservoir at one temperature directly into work without also rejecting heat to a cooler reservoir. That is, no heat engine is 100% efficient"
In the context of power generation from thermal energy, this means that any heat that is created must be rejected. Heat is most commonly rejected in the 3 types of cooling towers listed below: