Central concerns for electricity security are fuel security and adequacy and security of energy systems (IEA, 2016e). However, its interpretation is heavily influenced by national contexts, for example in terms of energy access, the energy mix and dependence on energy imports. For energy-importing countries (developed as well as developing), particular concerns are the resilience of energy systems to external supply shocks, the balance-of-payments effects of changes in international energy prices and diversification of energy suppliers (Yergin, 2006).