Stochastic Approach to Idle Discharge from Energy Reservoir

Abstract

Energy production is the main task of most multi-purpose water reservoirs. All water should flow through the turbines to produce electricity. Any idle discharge can be compared to potential energy production, taking into account the situation where the reservoir could be prepared to handle bigger future inflows. Of course, this problem is strictly connected with the prediction of inflows to the reservoir. In many cases, daily working time of a given water power plant is related to the current reservoir capacity and a short-time deterministic inflow forecast. This forecast is usually calculated on the basis of a rainfall-runoff model or from any other simple prediction model. But bigger inflows can sometimes occur in the nearest future. These inflows may be so big that they mdemand that we should start preparing ample reservoir capacity in order to avoid possible future idle discharges of water. The paper presents how to calculate the probability estimation of future idle discharges from a given reservoir.