Field-test performance models of a residential micro-cogeneration system based on the hybridization of a proton exchange membrane fuel cell and a gas condensing boiler

The energy transition brings focus on cogeneration systems, even at residential levels. One of the latter systems consists in a proton exchange membrane fuel cell (PEMFC) combined with a gas condensing boiler and a 220L domestic hot water tank. The system, fed by natural gas, is designed to provide the heat demands of residential houses and to participate locally in the electrical production thanks to the PEMFC of nominal constant power of 0.75kWel (and 1.1kWth). The boiler, sized for peak heat demands, can be chosen between four rated power versions from 11.4 to 30.8kWth. The machine is never electrically driven. This study has developed daily (and monthly) performance models of the system based on field-test results of two machines installed and monitored in Belgium for the whole year 2020. All models only require daily (or monthly) heat demands of the building as inputs but more elaborated (and accurate) models have been established considering operating temperatures and the demonstrated ability of the machine to modulate its heat rate output in real onsite applications. Finally, this paper has demonstrated that the daily PEMFC load factor (its daily electrical production) has a significant influence on the daily performance and therefore on the goodness of fit of the models. Unfortunately, the demonstrated PEMFC load factor is unexpectedly low for the monitored dwellings, probably due to the high level of complexity of the hybridization between the components of the system.