Dense urban environments present unique challenges for renewable energy integration. Retrofitting after construction completion is costly and inflexible, yet planners often lack tools to evaluate distributed solar and storage potential during the initial design phase. Researchers have developed a parametric simulation workflow embedded in Rhino/Grasshopper to address this gap, enabling architects to compare urban master-plan alternatives and their renewable energy performance in real time.
The Vienna case study examined the Kempelenpark district across four scenarios: the baseline master plan plus three alternative typologies (Tower, Linear, and Mix). The workflow combines hourly irradiation modeling, threshold-based roof and façade selection, simplified PV yield estimation, district electricity demand profiles, and battery dispatch logic. A custom ray-tracing algorithm provides rapid irradiation feedback during iterative design work, critical for keeping planners engaged during the conceptual phase.
Results showed the Mix typology achieved the highest annual PV output—3,356 MWh—across surfaces exceeding an economic irradiation threshold of 900 kWh/m²/year. Without storage, the system could cover approximately 30% of district electricity demand through solar generation. Battery integration significantly improved the picture: a 2 MWh economic storage configuration raised coverage to 40%, while an energy-oriented 2 kWh/kWp system pushed self-sufficiency to nearly 60%. Under 2023 cost assumptions, an optimized BIPV-battery system achieved a 10-year payback period.
The framework's primary value lies in its comparative assessment capability during early planning stages, when urban form decisions remain malleable. Rather than providing precise operational forecasts, the tool generates planning indicators that help architects and municipal planners understand how street patterns, building heights, and typological choices influence renewable potential. This integration of energy analysis into the parametric design environment represents a meaningful step toward climate-responsive urban development in northern European cities facing stringent carbon targets.
