Solar3D

Solar3D extends the GRASS GIS r.sun model to calculate solar irradiation on three-dimensional surfaces within virtual environments built from 3D city models, digital elevation models (DEMs), digital surface models (DSMs), and feature layers for urban energy and environmental analysis.

Key Features:

• 3D model integration: Extends the 2D GRASS GIS r.sun computation to a 3D context by incorporating inputs from 3D city models, DEMs, DSMs, and feature layers for solar radiation estimation.
• Handling of heterogeneous data: Processes large heterogeneous 3D city models, including models derived from oblique airborne photogrammetry-based techniques.
• Real-time calculations: Performs near real-time pointwise solar irradiation calculations over temporal scopes from daily to annual.
• Versatile surface analysis: Computes solar irradiation at arbitrary surface positions, including rooftops, facades, and ground levels, accounting for surface type.

Scientific Applications:

• Urban planning and design: Quantifies solar exposure to inform building design and urban morphology decisions for energy efficiency.
• Renewable energy assessment: Evaluates solar energy potential and supports placement and design considerations for photovoltaic systems in urban environments.
• Environmental impact studies: Assesses how urban configurations affect solar exposure and contributes to analyses of microclimates and urban heat island effects.

Methodology:

Extends GRASS GIS r.sun to 3D; processes inputs from 3D city models, DEMs, DSMs and feature layers (including oblique airborne photogrammetry-derived models); performs pointwise solar irradiation calculations accounting for day, latitude, surface type, and atmospheric parameters across durations from daily to annual and for arbitrary surface positions.