these contributions take in account the degree of diversity and supply origin of different energy carriers the efficiency of energy consumption by main the economic sectors and the state of the electricity generation infrastructure the values of weights determining the relative contribution of the demand infrastructure and supply branches are close to those used in the original sd model where they were adjusted to reflect the percieved vulnerability of the branches a higher weight indicates increased vulnerability as described below a maximal score refers to a country with low energy intensity developed electricity generation infrastructure perfectly diversified primary energy sources with the latter all domestically produced or imported from trustworthy sources on the contrary a score corresponds to a country with low energy efficiency an electricity capacity unable to satisfy the peak load and importing the totality of the energy carriers from unreliable sources