Assessing sustainability of long-term energy supply using desirability functions

The depletion of fossil fuels due to high energy demand poses an imminent threat to energy security. Sustainability of energy sources is prioritized to minimize the economic impact of oil supply disruptions. Several energy security indices and indicators had been developed to quantitatively assess the security of supply. However, studies concerning the cost of such risks were limited. Thus, a modification to currently used supply sustainability indicators is needed to express the risk score as a probability of disruption. In this study, a modification was applied using desirability function to convert the scores into scales. Long-term energy security was assessed based on reserves-to-production ratio and share in world export. A case study on the crude oil imports of the Philippines from 2007 to 2016 was conducted to demonstrate the proposed methodology. The desirability scores were weighted based on the share of each supplier to the total crude oil import. During the 10-year period, integrated sustainability risk scores reflecting a proxy probability varying from 1 to 8% were computed due to changes in suppliers and import shares. The study recommends consistent importation of crude oil from sustainable countries to minimize the sustainability risk. (C) 2019 The Authors. Published by Elsevier Ltd.