After the recent entry of the European Target Model in the Hellenic Energy Exchange (HENEX), the landscape regarding the fluctuation of electricity prices is still blurred in the current state-of-the-art. More specifically, following the introduction of this model, achieving an integrated European energy market while including a greater share of Renewable Energy Sources (RES) and improved energy efficiency systems creates competition between businesses and allows consumers to choose energy suppliers. Therefore, the main objective of this project is to propose to the University of Patras as well as Elin Verd S.A. a comprehensive scientific approach in order to use effective and specialized techniques so as to accurately predict Greek electricity prices while taking into account the high penetration of RES.