Deterministic Sizing of Integrated Facade Nodes for Smart Buildings

In the global transformation towards a sustainable energy system, the implementation of energy efficiency measures and demand flexibility play a crucial role. Dynamic window shading of building facades poses a great potential to reduce, shift, and modulate a building's electricity consumption by blocking solar heat gains and thereby avoiding expensive Heating, Ventilation, and Air-Conditioning (HVAC) operation to cool the building. However, the installation of dynamic facade systems is often cost-prohibitive with expensive building wiring and interconnection. An integrated direct current (DC) nanogrid is proposed instead, which eliminates any electrical interconnection, by combining all components - generation, storage, and shading element - into a self-contained unit. This study seeks to assess the unique design criteria of such Integrated Facade Node (IFN) system given infrequent but high-power use, coincidence of dynamic facade operation with solar renewable photovoltaic (PV) power generation, and unusual placement of the PV generator along the building facade. Optimal IFN sizes based on a deterministic sizing algorithm for a south facing building perimeter are analyzed and installation cost savings of $64,000 (65%) for a medium office building, with the potential to increase up to 91%, are presented.