Performance Assessment of Fuel Cell Micro-cogeneration Systems for Residential Buildings

Micro-Cogeneration fuel cells systems technologies are small modular power generation systems that in the near future will compete with conventional methods of energy supply. A micro-cogeneration fuel cells systems have significant preference related other traditional methods by technical performance and environmental emission and only have high capital cost disadvantage. The main use of micro-cogeneration fuel cells systems is residential application. The possibility of introducing a co-generation system with a proton exchange membrane fuel cell (PEMFC) for residential use is examined by a feasibility study. First, the structure of a system is constructed by calculating heat and material balances among the system components. Secondly, a model family is constructed from the results of a questionnaire on room layout, number of family members, and the number of electric appliances and consumption of electric power in multi-family building in Iran. Thirdly, calculating the electric power and hot water demand supply balance optimizes the scale of the co-generation system with a PEM for residential use. Finally, the running costs of this optimum system using city gas are considered. The results obtained show that the micro cogeneration fuel cell systems exhibit higher efficiency (79%) for heat and electricity generation with low level of CO2 emission (23% less than conventional systems). Also, the results have shown that the fuel cell technology is not economical at present and it cannot compete with the conventional technologies. However, this option will be an economical and suitable alternative in comparison with the other conventional technologies for power generation with respect to the near future fuel cells mass production, capital cost reduction, lifetime increase, emission importance and fossil fuel price increase.