The study took place in the framework of the “Long term Belgian energy outlook” published by the Federal Planning Bureau (FPB) every three years. In this context, the study aimed at elaborating and describing different scenarios of the evolution of the Belgian energy system in a European perspective. To fulfil this objective, the PRIMES model developed by E3-Modelling partners was used. Several scenarios were quantified, one of which was the Reference scenario. The Reference was based on the same assumptions as those underlying the Reference scenario released by the European Commission in August 2013 as far as global and sectorial economic activities, international energy prices and climate/energy policy context are concerned. In addition to the Reference, several alternative scenarios were designed, simulated and assessed in order to account for uncertainties related to the evolution of economic activity and fossil fuel prices, on the one hand, and for the EU energy and climate objectives beyond 2020, on the other hand.