Investigation of the effects of repowering options on electricity generation cost on Iran steam power plants

Many of Iran's steam power plants are old and inefficient. Repowering as an experimented and generable way can be an effective method for reconstruction of the old steam power plants. According to the power plant specifications, there are different repowering methods. In this paper, overall conditions have been considered for choosing the most appropriate method. Thermo-economical parameters are calculated for repowering a number of Iran power plants. Expenses for repowering an existing power plant are compared with those of establishing a new gas turbine plant or a combined power plant cycles. The cost of electricity generation are calculated and compared for three different scenarios: repowering of the steam power plant, building a new gas turbine power plant and building a combined cycle power plant. The results show that repowering options not only have considerable capacity for upgrading, but also provide the lowest cost of electricity generation.