Combined renewable resource exploitation: Implications for the all-island Irish electricity supply system

Most countries are increasingly focusing on the exploitation of combined renewable energy resources and balancing storage modalities to drive future power networks entirely with renewable generation. The transition plan, particularly in Ireland, is primarily driven by wind and solar energy, in combination with hydrogen storage. In this paper, we assess the full gamut of combined resource exploitation, focusing on the potential benefits of combining the relatively unexploited but significant marine renewable energy resources (wave and tidal) with more established renewable technologies, such as wind and solar. Specifically, this paper presents a complementarity assessment of four renewable resources, i.e. wave, tidal, wind, and solar, around the Island of Ireland, including Northern Ireland. The complementarity results demonstrate clear benefits of diversifying the resource mix, with the highest complementarity achieved by combining all four resources. Furthermore, we conduct an optimal storage sizing analysis for various resource combinations, considering both 100% renewable and transitional scenarios. This analysis reveals that maintaining some level of fossil-fuel generation, though non-ideal from a climate action perspective, may be beneficial in terms of the required storage size, and associated costs. Based on the optimal storage sizing results, we perform a techno-economic feasibility analysis for different storage modalities, finding that hydrogen storage may not be the best option for Ireland due to its lower cycle (turn-around) efficiency compared to other storage technologies. However, hydrogen can be directly used in other applications, such as transport and industry. Finally, we discuss the implications of these findings within the context of the all-island Irish electricity supply system, considering operational aspects, resource evolution, and policy considerations. • This paper assesses complementarity and storage sizing for Ireland utilising four renewables. • A high generation mix diversity provides highest complementarity for Island of Ireland. • For 100% renewable generation, increasing wind capacity beyond 7.65 [GW] requires more storage. • The findings are discussed in context of Ireland’s electricity system and policies.