Mitigating Curtailment Risks in Korea’s Renewable Future: Grid Simulation with Offshore Wind AEP and Transmission Scenarios

Curtailment risk is often perceived as an unavoidable consequence of rapid renewable expansion; however, such assessments frequently rely on simplified generation assumptions and static representations of the transmission network.

This paper presents a scenario-based assessment of curtailment risk in Korea that explicitly links offshore wind generation profiles with the staged delivery of transmission infrastructure.

The analysis integrates three key elements: realistic offshore wind generation profiles derived from project-level Annual Energy Production (AEP) data, alternative transmission reinforcement scenarios reflecting plausible grid delivery timelines, and forward-looking power system simulations incorporating seasonal and diurnal variations. By combining these elements, the study moves beyond generic curtailment narratives and provides a grounded evaluation of when, where, and under what conditions curtailment may arise.

Curtailment is quantified by translating simulation-based operating constraints into reductions in effective capacity factors, which are then applied to project-level AEP data. This approach preserves the temporal structure of both generation and network constraints and enables curtailment to be interpreted in commercially meaningful terms. Particular attention is given to distinguishing between structural curtailment—arising from long-term inadequacy of transmission capacity—and transitional curtailment driven by timing mismatches between generation deployment and grid reinforcement.

The results show that, under scheduled transmission delivery, curtailment remains limited and does not constitute a structural constraint on offshore wind deployment. Where curtailment occurs, it is concentrated in narrow seasonal and time-of-day operating windows and diminishes as planned grid reinforcements are commissioned. Sensitivity analysis indicates that higher curtailment levels under delayed transmission delivery are temporary and reflect transitional conditions rather than persistent system limitations.

By expressing curtailment as a reduction in effective capacity factor, the study provides a transparent link between technical system behaviour and AEP loss, enabling a direct 1 interpretation of curtailment risk from an investment perspective. The findings suggest that curtailment in Korea’s evolving power system should be understood primarily as a coordination challenge between renewable deployment and grid delivery, rather than as an inherent barrier to offshore wind investment. From an investment perspective, this distinction is particularly relevant in systems where transmission reinforcement is delivered in stages rather than as a single, upfront expansion.