Simulation-based framework for early-stage assessment of building-integrated photovoltaics and battery storage in urban district master planning: Vienna case study

Dense urban districts require decision-support methods that allow architects and planners to evaluate renewable generation, storage and demand interactions while the master plan is still flexible. This paper presents a simulation-based workflow for early-stage assessment of building-integrated photovoltaics (BIPV) and battery energy storage at district scale. The workflow is implemented in a parametric Rhino/Grasshopper environment and combines hourly irradiation analysis, threshold-based BIPV surface selection, simplified PV yield modelling, district electricity-demand modelling and battery dispatch. A custom ray-tracing routine is used to provide rapid irradiation feedback during design iteration. The approach is applied to the Kempelenpark district in Vienna, Austria, by comparing the original master plan with three alternative urban typologies: Tower, Linear and Mix. Under the simulated weather, demand and economic assumptions used in this study, the model outputs indicate that the Mix typology provides the highest annual PV production for surfaces above the selected economic irradiation threshold of 900 kWh/m²a, with an estimated annual yield of 3356 MWh. The results suggest that storage can increase the solar cover ratio from approximately 30% without storage to about 40% with a 2 MWh (0.60 kWh pro 1 kWp) economically oriented battery and to nearly 60% around the energy-oriented knee of the storage curve (2 kWh pro 1 kWp). The techno-economic analysis under the assumed 2023 techno-economic conditions reveals that an optimized BIPV-Battery-System can achieve a payback period of approximately 10 years under current market conditions. The main contribution of the paper is the integrated workflow and its demonstration for comparing master-plan alternatives, identifying promising BIPV areas and screening battery sizes. The reported values should be interpreted as comparative planning indicators rather than validated operational predictions.