“…For Haris Doukas et al [11] energy sustainability index, 8 indicators were selected: population density, GDP energy consumption, population-to-population production of RES, population consumption of fossil fuels, RES electricity, RES heating, RES/fossil fuel electricity generation, and population-to-peak tourists. A similar division was used to calculate the Household sustainability index for heat generation [12]. Another example of using a composite index to assess sustainability can be found in [13], this article includes not only the economic, social and environmental dimensions, but also an institutional dimension that supports the other dimensions.…”