Energy security assessment methods: Quantifying the security co-benefits of decarbonising the Irish Energy System

Energy security is an interdisciplinary concept. Its definitions leaves it vulnerable to exploitation as a justification for energy policy instruments. The extensive literature has yet to converge to formulate a unified definition of energy security and many outline a multitude of methods of measurement, such as the Supply/Demand index applied here in modified form, but also the Hirshman-Herfindahl Index, the Shannon Index for fuel diversity, and others. However, many of these index methods do not explicitly take into account the techno-economic interdependencies which influence energy security within the energy system. This paper reviews the literature to establish an energy security assessment method considering perspectives from sovereignty, infrastructural robustness, and market resilience. The aim of the paper is to provide a transparent data rich method and assessment of energy security by means of an application of a systemic energy security index to historical data and potential projected techno-economic energy system scenario analysis for a decarbonising Irish Energy System.