Fuel consumption analysis of a residential cogeneration system using a solid oxide fuel cell with regulation of heat to power ratio

Solid oxide fuel cells are suitable for heat and power cogeneration systems for their high electric efficiency and heat to power output ratio. Although commercial solid oxide fuel cells use heat from the exhaust to obtain hydrogen through natural gas reformation, recent progress in hydrogen generation technologies allows us to use pure hydrogen instead of natural gas, and utilize the exhaust heat for other purposes. A residential cogeneration system using a solid oxide fuel cell is proposed in this study, where the heat to power output ratio is varied to match the electric and hot water demands of a residence in Japan. Seasonal fuel consumption of the system is calculated and compared against a similar system without hydrogen addition, and to the conventional system. The proposed system shows a considerable reduction in fuel consumption, while almost reaching complete independence from the power grid.