Impact of renewable energy on spinning reserve based on economic dispatch

Abstract

This paper demonstrates economic dispatch of generation system of Thailand at the time period which the net demand increases fastest. The net demand can be calculated by subtracting output power of renewable energy generation and non-dispatchable generations from actual electrical demand. Genetic algorithm is employed to determine the optimal set of committed power plants. Not only operating cost is the objective function of the optimization, but also expected outage cost caused by the failures of power plants. Since the outages are random by nature, in order to achieve the minimum total cost it is necessary to include spinning reserve into the optimization. Spinning reserve is a reserve of online power plants used by system operator to respond to load changing and unexpected events such as power plant outages and sudden dropping of output power of renewable energy generations. The results of this paper are the number of committed power plants, spinning reserve and total cost. The numerical simulations show that when more renewable energy generation is installed, amount of required spinning reserve is increased and more power plants are committed.