3D solar maps for the evaluation of building integrated photovoltaics in future city districts: A norwegian case study

Three-dimensional (3D) solar maps based on Radiance simulations are presented for a future city district in southern Norway. The surface mapping method provides the commercial developer with a practical tool to evaluate the potential for building integrated photovoltaics (BIPV). The solar maps identify the optimum roof and facade areas available for solar energy utilization. The importance of BIPV and facade utilization in new city developments is discussed, along with key questions raised by the commercial developer regarding the practical implementation of BIPV solutions. Based on feedback from the building industry, a simplified model has been implemented to evaluate surface areas producing a profit or a loss over the PV system lifetime. As tilted photovoltaic (PV) modules installed on flat roofs are not building integrated, three simulation variants have been performed for flat roofs with a small inclination up to ten degrees. For some buildings this will give a small gain in annual PV production and payback time. The resulting 3D solar maps give the developer a possibility to review early-stage plans in terms of building shapes and positions in the landscape, in order to maximize utilization of the available solar resource. This enables cost- and energy-efficient development of nearly zero-energy buildings in future city districts.