This Diploma Thesis deals with the issue of Renewable Energy Sources and its association with energy poverty. In particular, the purpose of the work is to highlight the phenomenon of energy poverty and to show its mitigation potential through the use of Renewable Energy Sources. In the paper are presented a number of empirical studies in Greece and in the European Union that approach this issue in order to give as much as possible a more holistic and realistic approach. As the phenomenon of energy poverty has been noted in recent years, it has also begun to work at institutional level, both in the European Union and in Greece itself. In the case of Greece, energy poverty is mainly due to the poor condition of the building stock, the way of heating (oil) and the deteriorating economic conditions.