Abstract

Residential fuel cell cogeneration systems are being targeted as energy-efficient alternatives to conventional power plants to heat and power our homes. However, when a fuel cell is controlled to meet a house's electrical load, there may be an excess amount of heat that is available in the summer when a house's thermal requirements are minimal. The objective of this work is to investigate the feasibility of coupling an adsorption system to a residential fuel cell cogeneration system for the seasonal storage of the fuel cell's surplus thermal output. A mathematical model of an adsorption storage system is developed, by applying first principles, and implemented into the ESP-r building energy simulation program. The model is validated using published data and verified using a sensitivity analysis technique. Finally, the predicted annual energy performance of a house served by a fuel cell cogeneration system coupled to an adsorption storage system is compared to the predicted annual energy performance of two alternate heating systems using ESP-r, taking into account the dynamic nature of the house's electrical and thermal loads. For the set of operating conditions considered in the study, the adsorption storage unit is able to improve the overall energy performance of the residential fuel cell cogeneration system in the winter but not in the summer. Simulation results show that factors such as the utility grid's generation source and the capacity of the adsorption storage unit influence whether the energy performance of the residential fuel cell cogeneration system surpasses the energy performance of a conventional heating system