Assessment of effective dependable capacity for renewable power plants in Thailand´s power system

This paper presents a study of the dependable capacity of renewable generation, undertaken within System Planning Division, Electricity Generating Authority of Thailand (EGAT), in 2011. In the study, reliability evaluation methods are chosen for an assessment of dependable capacities associated with system reliability indices to determine specific information for the long-term planning purposes. A review of generation profiles of renewable power plants is undertaken with specific targets of six sources, i.e. solar, wind, biomass, biogas, municipal solid waste, and mini-hydro. Obtained data of generation profiles are used to develop the probabilistic criteria for generation adequacy assessment, representing the nonlinear relationship of conventional and renewable power plants as a function of availability for system capacity planning. Later, the paper offers a mathematical model for dependable capacity assessment. The Probability Density Function (PDF) is adopted for different reliability indices to evaluate the dependable capacity on the basis of probabilistic actual generation profiles from the obtained data of power plants. Reliability evaluation methods - chronological and probabilistic - are deployed throughout analytical process. Lastly, the paper provides results from the analyses of the country´s survey data, along with a description of the dependable capacities onto six different renewable generating resources and variety of studied periods.