HIGHLIGHTS

Renewable energy curtailments were first implemented on Jeju Island in 2015 and have since been occurring on the mainland starting in 2021. However, it is difficult to locate documentation that clearly explains the specific reasons for these regional curtailments.

The causes of curtailment can be categorized into oversupply, transmission constraints, lack of reserve power, lack of inertia, and inadequate inverter function, primarily occurring in the Jeju and Honam regions. Curtailment in Jeju is primarily due to a lack of inertia, while in Honam, it is mainly attributed to inadequate inverter function and transmission constraints.

Curtailment increases uncertainty for operators of solar and wind energy, thereby impeding the penetration of renewable energy. To reduce this uncertainty, it is essential to have transparent data disclosure regarding curtailment. However, South Korea has not yet achieved transparency in disclosing the source, location, and amount of curtailment.

This issue brief aims to clarify the concept of curtailment for non-power system professionals by analyzing the various causes of curtailment in Korea and introducing examples of curtailment policies and data disclosure from other countries. Based on these analyses, we recommend that transparent data disclosure and clear curtailment policies be established as prerequisites for mitigating curtailment and promoting renewable energy.

 Curtailment, power grid, solar, wind, data transparency