SCHEDULING OF HYDROPOWER RESOURCES IN A FREE MARKET

Abstract

In order to preserve the stability of electricity supply, power producers have to provide ancillary services in addition to energy production. Hydropower resources are believed to be the most efficient source of ancillary services because of their good dynamic flexibility. This thesis studies an optimal bidding and operation decisions of conventional hydropower plants and pumped storage plants operating in simultaneous markets for energy and ancillary services by considering all the parameters of the hydro units, and water availability. The model implications are illustrated on various numerical examples of different hydro resources operating in free market. In this report two formulations are presented: (1) a nonlinear mixed integer program for conventional hydropower optimization, also for the combined operation of hydro with pumped-storage plant and (2) a linear mixed integer program for scheduling of a single pumped-storage plant. These formulations optimize the hydro power generation scheduling to get maximum revenues for the power producer company under the free market environment. In fact, the profit due to participate in the energy and the ancillary service markets is maximized ignoring the power balance in the system.. The constraints includes the upper and lower reservoir capacities, efficiency and capacity of the generating and pumping for pumped-storage plant, and permissible discharge capacity and in-stream flows, water travel time, storage-release relationships, and permissible fluctuation of the reservoir water for the convention hydro electric plants. Both formulations are general and are applicable to any hydro electric system. The hydro power scheduling is done for time horizon of 24 hour and 168 hour with the time interval of 1 hour and by considering the start-up costs of hydro power plant and operating cost of pumped-storage plant.