Techno-economic and Exergoeconomic Analysis of a micro cogeneration system for a residential use

The aim of the study is to present an economic analysis of a micro cogeneration system using financial analysis (energy view) and exergoeconomic analysis (exergy view). This system uses a natural gas-fueled 30 kW microturbine to generate electricity, and to produce hot water by recovering energy from the waste heat in the exhaust gases by using a heat exchanger, which serves as the drive source of an absorption chiller with a nominal capacity of 35 kW. In the financial analysis economic indicators such as payback, net present value and internal rate of return were used to verify the economic feasibility of this system, while in the exergoeconomic analysis, the Theory of Exergetic Cost was used to determine the exergetic monetary costs. A thermodynamic model was developed on the EES-32 (Engineering Equation Solver) platform. On applying the financial analysis, the results showed that the micro cogeneration system is feasible with positive values of R$ 206,540.00 for NPV, 27% IRR and a 6-year payback. Based on the exergoeconomic analysis, the cogeneration system is also feasible since the monetary cost of the electricity is lower than that charged by the electricity company but this is only possible after the 5 year.