Operating Policy for a Pumped Storage Hydropower System

Operation of a pumped storage system as dictated by the price of electricity and capacity limitation on other generating plants is considered. The formulation incorporates constraints on permissible fluctuation in the upper reservoir as demanded by the lake shore property owners and recreational needs, lower reservoir capacity, downstream channel capacity and flood stage consideration, in-stream flow needs, efficiency and capacity of the generating and pumping units, and storage release relations. The time dependent cost data clearly governs the operating policy of a pumped storage system. Several different cost patterns are considered to analyze variations in the solution. Because the pumped storage plant is part of a large system involving different types of generating units, the plant can be put into use when other plants can not sustain the load. However, the data pertaining to the whole system is hard to obtain. Thus the scenarios are analyzed by imposing various limits on the total production capacity. This permits an analysis of variations in actual operations that took place and the model recommended operations. The mathematical formulation results in a nonlinear integer program.