Evaluation of SOFC-CHP’s ability to integrate thermal and electrical energy system decentrally in a single-family house with model predictive controller

Abstract

The integration of natural gas powered solid oxide fuel cell combined heat and power (SOFC-CHP) unit into a decentral residential energy system consisting of solar thermal collectors, photovoltaic with both thermal sensible heat storage and lithium-ion battery is simulatively evaluated. The system also includes gas boiler and electrical grid as back up. The system is investigated along with status quo controllers and how an implementation of a model predictive controller (MPC) and seasonal shutdown of the FC-CHP influences the performances of the SOFC-CHP. The performance is also analysed with two different single-family house German energy standards: Sonnenhaus (relatively new high renewable fraction house) and WSchVO95 (old house as per the year 1995′s standard). The results show that via SOFC-CHP 100% self-supply of the electrical loads is possible and a 10% increase in decentral system self-consumption fraction by introducing MPC control. Also, it could be seen here that the MPC control for FC-CHP and the use of FC-CHP for the old WSchVO95 building has more advantages than anticipated. SOFC-CHP seasonal shutdown along with +12% & +7% self-consumption fraction at the expense of +5% & +2% electricity import in Sonnenhaus and WSchVO95 buildings respectively also increases photovoltaic, solar thermal and battery use.