Economic Feasibility Study of Some Cogeneration Plants for a Local Energy Center

Abstract

The present paper describes a case study on economic evaluation of some alternative cogeneration plants to be installed into a local energy center in a district heating and cooling project. First, energy demands are estimated according to the construction plan of buildings. Then, a simple gas turbine cycle plant, a combined gas and steam turbine cycle plant, and a steam injected gas turbine cycle plant are selected as alternatives for investigation together with a conventional plant. Operational strategies are assessed so as to minimize the hourly running cost using an optimal operational planning method. Lastly, long-term economics for alternative plants are evaluated on the basis of the annualized costs method, and they are compared with one another. Through the study, it is ascertained that the annual total cost is minimized by introducing the conventional plant at the first stage with low energy demands, and by adding the cogeneration plant, in particular, of the steam injected gas turbine cycle type at the second stage with high energy demands.