The paper presents an attempt to select, define and apply a set of sustainability indicators for the energy system assessment. Starting from the general sustainability concept, a set of indicators is defined reflecting specific criteria for the energy system evaluation. Particular attention is devoted to the resource, environment, social and economic criteria. Among these groups of criteria there are individual indicators emphasising respective aspect of the sustainability concept. This approach has its limitation due to the lack of data for serious consideration of the system. But it should be anticipated that these excises might serve as the guidance for the eventual future application. Also, this methodology for the assessment of energy system will become an useful tool only if it proves useful in the engineering practice. The example under consideration is an island with only individual consumption to be satisfied with solar, wind, biomass and oil-fired power plant which represent four options under consideration. The set of indicators is defined and determined with the aim to demonstrate the method of decision making procedure in selecting the option which meet selected indicators numerical values and constrain reflecting the non-numeric information of weighting factor for the determination of general criteria for the selection of appropriate option.