Models for energy systems development planning

The article discuses some classification criteria for mathematical models for energy systems development planning. Also based on that classification a review is provided of the relevance of some models to the energy system planning in Bulgaria.Large part of the already existing classifications are either out of date or incomplete. The last is partially due to the fact that each classification is meant to serve a particular purpose. Never the less we consider that the development of a fresh classification and an evaluation of different models suitability for energy system planning in Bulgaria would be an useful endeavor.