ESS 기반재생에너지 출력제한 경감을 통한 효율적 저탄소 전력체계 구축 모색-2025년 제주도를 중심으로-

Due to the ambitious carbon net-zero target by 2050, deployment of variable renewable energy (VRE) sources has been accelerated. However, the duck curve problem caused by massive generation of solar photovoltaics increases the possibility of VRE curtailment, leading to increasing power supply cost due to reduced capacity factor of VRE. This study estimates hourly amount of VRE curtailment and analyzes an energy storage system (ESS) as a viable option to mitigate curtailment based on the Jeju Island power system in 2025. The power system optimization model called PLEXOS is used to estimate the amount of curtailment, and a profit maximization model is applied to analyze the economic feasibility of ESS. The result shows that the economic feasibility of ESS was higher when applying system marginal price (SMP) 0 KRW/kWh when VRE is curtailed compared to the case of applying SMP on the mainland. At the ESS capacity that can achieve 25% total curtailment reduction, an internal rate of return (IRR) of 4.99% is achieved; with a lower ESS capacity, an IRR of 6 ~ 8% can be achieved. This result suggests that ESS is a viable option to reduce VRE curtailment to an appropriate level to operate such a power system efficiently.