Because of high-energy demand, population increase and exhaustion of fossil fuels, renewable energy is being utilized around the world especially for hybrid systems. The hybrid system should be optimally sized hence the aim of the study is to determine the technical and economic evaluation of a standalone and on grid hybrid system to supply power to the Department of Electrical and Electronics Engineering in Eskişehir Technical University. Hybrid optimization model for multiple energy resources (HOMER) program is used to achieve the optimal configuration of the standalone and on grid hybrid system and these systems are compared to each other to see the most economical one according to the net present cost (NPC) and cost of energy (COE). The result revealed that the most optimal configuration of the two systems is PV/Grid hybrid system with 198kW PV panel and the grid. It has NPC and COE of $1.68M and 0.176$/kWh but is not environmentally friendly as a standalone system due to low renewable fraction (RF). Overall, by using hybrid renewable energy systems (HES), the study is trying to solve the problem of reliability, cost and environmental concerns of the conventional energy sources.