After the recent war (1992-1995) the country B&H includes the two entities and given these two entities the country is politically divided. Also the country is in transition process with neglected economic circumstances and the energy sector is supported via high subsidies. There are some pollution taxes but not enough to stimulating the more sustainable energy sector development. Under those circumstances the management of JP Elektroprivreda B&H (one of three state owned public enterprises for generation and distribution electricity in B&H) is committed to investing in renewable energy but still there is no final decision on the percentage share of RES or the state BH has prescribed obligated share of RES. So the main objective of this paper is to investigate optimal share of renewable sources to be introduced into power system of EP B&H. Analysis, which takes into account three different scenarios defined according to the percentage share of new renewable sources. Low (5% of RES), Medium (10% of RES), and High (20% of RES), was made. According to the evaluated indicators and the analysis, it can be concluded that scenario of introducing 10% of new renewable sources by year 2025 will bring the best effects to the sustainability. (C) 2012 Elsevier Ltd. All rights reserved.