The Greek energy system is one of the most carbon intensive energy systems in Europe. Hydrocarbons and solid fuels (lignite) cover over 80% of the final energy demand. The main objective of this work is to build energy scenarios for the future - with a focus on the electricity production system - and explore how these scenarios are reflected in economic, environmental terms and in terms of energy efficiency. The main tool which is used in the scenario analysis is LEAP (Long range Energy Alternatives Planning System). The scenarios are essentially the result of developing "storylines" driven by the uncertainties which cannot be controlled by the analysts or decision makers, and technical and non-technical options the analyst or decision maker may choose from. A set of uncertainties is considered as a possible future or storyline, and one or more options can be selected as a possible strategy. The combination of a storyline and a specific strategy gives a scenario. The main uncertainties for the Greek energy system are identified and various technical options are explored. Rather than using a model which leads to optimum strategies from a set of alternatives, the model in use will apply different strategies. (C) 2012 Elsevier Ltd. All rights reserved.