Analysis of Wind Energy Curtailment in the Ireland and Northern Ireland Power Systems

Abstract: The All-Island power system (AIPS) of Ireland and Northern Ireland currently accommodates up to 75% of system non-synchronous penetration (SNSP) (e.g., wind). These unprecedented levels of renewable penetration challenge the operation of the power system. The AIPS is not always able to accommodate all of the available renewable generation due to binding operational and technical constraints. In this context, this paper analyses wind energy curtailment in the AIPS using actual data. It is found that there is a positive correlation between the installed wind capacity and curtailment levels, and that the trend is that these levels increase. The paper also shows that the main driver for curtailment in AIPS during 2020-2021 was the operational constraint that imposes a minimum number of conventional units online (MUON) (80% of the time), with the SNSP limit accounting for less than 20%. Other system-wide limits, such as rate of change of frequency (RoCoF) and inertia are found to have a negligible impact on wind curtailment.