Computer Search for Economical Operation of a Hydrothermal Electric System [includes discussion]

This paper describes the use of a high-speed digital computer for the purpose of searching for economical modes of operation in a mathematical model of a hydrothermal electric system. The minimization of annual operating cost is treated as a problem in the calculus of variations. A gradient concept is employed to successively seek time schedules of water use which reduce annual operating costs. Such reductions are achieved partly by increasing the energy yield, partly by sacrificing energy yield at one time to reduce high operating costs at another time, and partly by reducing the violation of prescribed rules of operation.