OPERATION POLICY OF UPPER KOLAB MULTIPURPOSE RESERVOIR

Abstract

This thesis aims at scheduling of releases from the Upper Kolab Multipurpose reservoir. Water from the reservoir shall be utilised for generation of hydropower to meet the power demand of the state of Orissa in combination with thermal generation and generation from other hydropower plants, Releases from the power house shall be diverted for irrigation. Objective of the study is two fold : firstly to plan an integrated operation of the Kolab reservoir for power gene-ration in - combination with thermal generation and secondly to examine the storage requirement for the downstream pond on the tail race to meet irrigation demand. Reservoirs are naturally to be operated in stochastic environments. However, the present study is to develop a model using historical flow data (deterministic model) . Optimal management policy will use the reservoir to even out thermal generation as far as possible throughout the planning horizon. Marginal cost of thermal generation and marginal value of water are key factors in optimal reservoir operation, The marginal cost of thermal generation should be equal to marginal value of hydropower generation, . which is otherwise the marginal value of water. Hydropower will substitute thermal power when cost of thermal power generation is high. The methodology used is dynamic programming. The plann--ing horizon considered is one year divided into monthly time periods. Storage trajectories are developed for different levels of hydrothermal combination. Saving in cost of thermal genera-tion due to generation of hydropower is computed for each ' trajectory. The trajectory which corresponds to maximum saving in cost is optimal. It is also ensured that the reservoir goes through a full cycle of operation starting and ending with full reservoir, Storage requirement at the downstream pond depends upon the releases from the power house and irrigation demand. If releases are made in conformity with irrigation demand, no storage would be required. Such a situation would involve an increase in cost of thermal generation. The economic impact of the two policies are obtained and discussed. Other suboptimal solutions for power generation were examined to see whether lower storage requirement would justify adopting such a pclicy. However it was found that other trajectories did not result in lowering the storage.