In this paper, we aim to contribute to the development and use of more formal notions of energy security, by providing an overview of available indicators for (long-term) security of supply and discussing the strengths and weaknesses of these indicators. It is important to define energy security before discussing the merits and drawbacks of the various indicators. From the available literature, it is obvious that distinct perspectives on the meaning of the concept exist. Therefore, we will first try to frame the concept on a level of abstraction such that currently existing visions can be included. Next, we discuss indicators for energy security that have been proposed over the years. These are reviewed in order to attain insight into their conceptual differences and the perspectives on energy security from which they were conceived. This allows for a schematic ordering of the indicators with regard to the elements of energy security that the indicators focus on. Thus an overview of indicators is provided with regard to their emphasis.
The concept of energy security is widely used, yet there is no consensus on its precise interpretation. In this research, we have provided an overview of available indicators for long-term security of supply (SOS). We distinguished four dimensions of energy security that relate to the availability, accessibility, affordability and acceptability of energy and classified indicators for energy security according to this taxonomy. There is no one ideal indicator, as the notion of energy security is highly context dependent. Rather, applying multiple indicators leads to a broader understanding. Incorporating these indicators in model-based scenario analysis showed accelerated depletion of currently known fossil resources due to increasing global demand. Coupled with increasing spatial discrepancy between consumption and production, international trade in energy carriers is projected to have increased by 142% in 2050 compared to 2008. Oil production is projected to become increasingly concentrated in a few countries up to 2030, after which production from other regions diversifies the market. Under stringent climate policies, this diversification may not occur due to reduced demand for oil. Possible benefits of climate policy include increased fuel diversity and slower depletion of fossil resources.