The power industry has adopted Heat Rate as the standard method of evaluating power plant unit efficiency. Net unit heat rate (NUHR) is the number of British thermal units (Btu) in fuel required to generate each kilowatt-hour of electrical energy delivered to the grid. Many things affect a power plant unit's NUHR. Among these things are some key controlled and/or monitored operating parameters that affect efficiency. Knowing these parameters, how much they affect unit efficiency, and conditions that can prevent them from being operated at their optimum level is important for maintaining efficient unit operation. The Performance Parameters training course list several key operating parameters that affect efficiency. It describes problems that can prevent key operating parameters from being operated at optimum level. It also shows how to calculate the approximate extra fuel cost associated with operating a key performance parameter off design value. Performance Parameters is part of the Efficiency, Reliability, and Environmentally Sensitive Operations training series.