Growing demand for electricity, reduction of fossil fuels, pollution from fossil fuels, and the importance of energy security have made it essential to plan for the use of alternative power generation technologies. In this paper using a mathematical programming and power industry data, the optimal share of different technologies for power generation consists of combined cycle gas turbine, steam, gas turbine, small wind, big wind, small photovoltaic, large photovoltaic, solar-thermal, small hydroelectric, large hydroelectric, nuclear and geothermal has been determined during 2016-2040. The purpose of the mathematical modeling is to determine the combination of possible supply options at the lowest cost so that they are able to meet the energy demand. The results showed that the share of gas consuming technologies will decrease dramatically, replacing mainly with renewable technologies. Solar and wind power plants will be the most important renewable technologies and will have a significant share in the last years.