LAUSR

Abstract Member States have published National Energy and Climate Plans with challenging variable renewable electricity (VRE) targets. As VRE has a high peak to average output, the Single Electricity Market of the island of Ireland (SEM) will need to consider how best to balance the lost value of curtailment against the extra costs of higher Simultaneous Non-Synchronous Penetration (SNSP), more interconnector capacity and/or more storage. The paper develops a spreadsheet model to explore these options for the 2026 VRE targets in the SEM and her neighbours. Raising SNSP from 75 % to 85 % reduces curtailment from 13.3 % to 8.0 %, saving 1338 GWh/yr of spilled wind. Adding the Celtic Link of 700 MW at SNSP of 75 % reduces curtailment to 12.4 % and saves 235 GWh. Adding 100 MW of batteries saves 19 GWh/yr, but the costs of delivering these savings are high. The marginal spilled wind can be four times the average, creating a potentially significant market distortion and reducing the value of adding further VRE.