Rational use of energy, exploitation of renewable energy sources (RES) and ensuring energy self-sufficiency are some of the key issues considered by European Union (EU) and Latvian energy policy. Until now sustainable energy system development in Latvia is addressed mainly on national or local level. Yet regional municipalities have significant role for influencing the decision-making processes in their territories, regional administration possibilities for workiong on development of regional energy systems are not fully recognized and used. The aim of this research ”Evaluation of Possibilities for Using Renewable Energy Sources in Latvia until 2020” is to develop 3 scenarios for RES in Latvia, based on regional energy demand analysis and considering legislation and technology development. One of the scenarios will include maximal use of solar energy potential, the second scenario will be put towards maximal use of wind potential and the third scenario will be developed including extended use of available biomass resources.