This paper is to investigate various renewable based hybrid systems with five minimum renewable penetration rates (RPR) for Pinarhisar Educational Campus in Kirklareli University, to present the effects of making the system more sensitive to the environment on the total net present cost (NPC) and cost of energy (CUE) and also to search for the optimum configuration of the hybrid systems. Yearly wind and solar data are considered in this study. Optimal stand-alone and grid connected hybrid systems with different minimum RPRs, are determined and analyzed in detail by using HOMER software and compared among themselves considering CUE, total NPC, emission rates. Additionally, sensitivity analysis is performed to determine the cost of generating the cleaner energy from the hybrid systems. As a result, it can be highlighted that gradual increases in the total NPC and CUE occur in the region where RPRs are between 0 and 70%, and that there are dramatic increases in both the total NPC and CUE for the RPRs above 70%. Moreover, emission rates for CO2, SO2 and NOx basically decrease as RPR increases from 0% to 90% and they decrease linearly until RPR is 80% while they are nearly zero for the values more than 80%. (C) 2013 Elsevier B.V. All rights reserved.