Central cogeneration units in Athens-an economical approach

The work presented in this paper concerns a computer model for the economical assessment of investments in the cogeneration field. All economic elements of the investment are taken into account and, in combination with the necessary technical data, the model calculates the cash flow of the entire investment and of the equity as well as some basic indices for the economic assessment such as the net present value, the internal rate of return, the discounted payback period and the benefit-to-cost ratio of the cash flow above. In a previous work by the F. Karagiannis (1998), a prefeasibility study has been undertaken by the Strategy and Planning Department of the Public Power Corporation of Greece on the operation of central cogeneration units (CHP) in Athens, that will supply with thermal and electrical energy three groups of buildings. The obtained results were encouraging and a continuation of the study has been decided. The above mentioned model has been applied and a sensitivity analysis has been realized. The results that the model gave show that the project is economically viable under certain conditions. Basic parameters directly affecting the project's viability are the initial investment cost, the fuel cost and the sales price of the produced electricity.