천연가스 복합발전기 정비비용의 결정요인 분석 :재생에너지 확대의 영향을 중심으로

The proportion of renewable energy generation facilities in South Korea has increased significantly due to the renewable energy portfolio standard system implemented in 2012. The most installed renewable energy in South Korea is solar power (SP) generation, which is called variable or intermittent renewable energy. In response to the intermittency of SP generation, the number of startups of NG combined cycle power plants has been continuously increasing. This is expected to have a significant impact on the increase in maintenance costs of natural gas (NG) combined cycle plants. This study analyzes the determinants of the maintenance costs using operational performance data from 2011 to 2022 of a specific NG combined cycle power plant located in Incheon. Infleunce factors include generator operation rate, utilization rate, number of starts, power system demand, and the ratio of SP generation to NG power generation. For the analysis, the least squares method, which is widely used in the literature, is applied. In addition, autocorrelation problems that frequently occur in time series data are tested and dealt with appropriately. As a result of the analysis, it was found that the number of the generator starts and the ratio of SP generation to NG power generation had a positive effect on the maintenance cost of the NG combined cycle generator. In particular, it is noteworthy that the increase in SP generation has a significant effect on the increase in maintenance costs of NG combined cycle plants. The results of this study can be used as an importance reference when preparing a reasonable compensation system for the stable power supply contribution of NG cycle plants.