This paper presents an assessment of the renewable energy potential in Romania using a clustering based data mining method. The available data on installed capacity, level voltage, type of renewable technology and geographical location the renewable energy potential for electricity generation was mapped into representative zones using K-Means clustering algorithm. For each zone, the potential was assessed on voltage level and renewable energy generation technologies (wind, solar, hydro, biogas, biomass, and cogeneration). The zones obtained can be a useful working tool for retrofitting substations, upgrading of transmission and distribution lines and also for redesigning them at different parameters with respect to the overload. This information may enable the creation of specific programs to improve planning and development of the electric networks in Romania. (C) 2014 Elsevier Ltd. All rights reserved.