Wind-hydro-gas turbine unit commitment to guarantee firm dispatchable power

The randomness and intermittence of wind power require additional reserves provided by thermal generators. This creates difficult scheduling of generation, causing thermal generators to start up or shut down frequently, or to operate at low efficiency and high fuel consumption state. If not, some wind power will be curtailed and wasted. This paper examines the operation of a hybrid system made up of a wind farm, a pump storage hydro and conventional thermal generation units consisting in a combination of a heavy-duty and an aeroderivative gas turbines. In order to seek an optimal approach to deal with the uncertainty of increasing wind power and ensure both the efficient operation of thermal generators and full use of wind energy, two different control strategies have been proposed and compared: (i) a "custom" in house developed strategy and (ii) an "optimal" strategy based on Dynamic Programming. Using actual generation data of a wind farm, the operation of hydro power plant and gas turbines are obtained with the aim of compensating differences between actual wind generation and load demanded. Natural gas fuel consumption and average gas turbine efficiencies during the analyzed time period are calculated along with number of units starts-up