Why Seek High Efficiency

However it is intuitively obvious, there are two explicit purposes for seeking maximum efficiency in power plant practice:

• The higher the effectiveness, the smaller is the amount of fuel needed to accomplish a specified task, therefore resultant in lower cost for fuel, slower fuel resource depletion, and less environmental harm in the extraction and combustion of the fuel.

• Since the efficiency is forever less than 100%, from the law, whatever energy is not strike for work should be discarded to the atmosphere and disposed of in some manner. Usually, about two-thirds of the energy in the fuel will be discarded, partially to the environment via the stack, and partially to the cooling water. Therefore, higher the efficiency smaller is the waste energy to be disposed of [Q2 = Q1 (1 – η)].

Thermal pollution from the nuclear power plants is larger than that from fossil-fuel-fired power plants for this cause. The efficiency of the nuclear power plant is less than that of its fossil fuel complement since the practical upper temperature limit of the previous is less, being restricted by the materials that should be employed to have the fissionable substances. For illustration, an identical power output of 500 MW, supposing an efficiency of 40% for a fossil fuel plant and 30% for the nuclear plant (i.e., a reduction of 25%), it can be illustrated that the heat refusal in the latter situation is higher by 56%.