PV Planning · 3D Roof Model · Shading

Shading analysis from 3D models

PV planning needs more than a good-looking roof photo. Shading is spatial, caused by chimneys, dormers, parapets, nearby buildings, trees, and the local horizon. A 3D model reconstructed from supplied imagery makes that geometry usable for planning.

12 min readVoxelia 3DGermany, Austria & Switzerland
Az/Elsun positionazimuth and elevation per timestamp
Horizonshade horizonPVGIS supports horizon information
3Droof contextobstructions and surroundings
3D roof model with shading-relevant obstructions for PV planning

For PV planning, roof area alone is not enough; obstruction geometry and context matter.

What 3D PV shading analysis actually provides

Shading analysis is not just a visual check for shadows. PV planning needs to know which roof zones are affected by real obstructions and whether that information can be handed off as usable geometry.

Voxelia turns supplied imagery into 3D models, orthophotos, CAD handoffs, or viewers. The value is in preparing image data for planning, not in selling drone flights.

Important distinction

A 3D model is a geometric shading basis, not a full energy-yield simulation by itself.

Required data for a dependable shading basis

The dataset must show the roof and the objects that cast shadows. A set of images that only shows the module field cannot model a nearby chimney or higher neighboring roof outside the frame.

Relevant inputs include scale, orientation, roof pitch, obstruction height, and whether the local terrain horizon matters.

ScenarioPhotogrammetryLaser ScanRecommendation
Chimneys, dormers, vents, parapetsVery suitableUsually not requiredDerive a 3D roof model with obstruction heights and exclusion zones
Neighboring building casts shadeSuitable if visibleOnly for missing geometryCapture or provide the roof context, not only the target building
Bankable yield forecastGeometric basisGeometric basisUse PV simulation software and weather data in addition

Workflow from supplied images to PV shading basis

The workflow starts with the planning target: layout check, CAD handoff, viewer, or PV simulation input.

  1. 01

    Review imagery and planning target

    Check visibility of roof planes, obstructions, ridges, eaves, and neighboring geometry.

  2. 02

    Stabilize scale and orientation

    Use references, EXIF/GPS, GCPs, or existing CAD data where available.

  3. 03

    Reconstruct roof model and obstructions

    Generate a robust reduced geometry instead of an unnecessarily heavy visual mesh.

  4. 04

    Prepare PV handoff

    Deliver viewer, CAD, orthophoto, mesh, or documented exclusion zones depending on the workflow.

Voxelia focus

3D roof models become valuable through the right PV handoff

For solar planning teams, supplied imagery is prepared into 3D roof models, orthophotos, CAD outputs, or viewers for clearer shading and layout decisions.

Useful outputs for solar teams

A useful shading analysis is a planning dataset, not just a colored image.

FormatBest forPractical note
3D roof modelModule layout and obstruction reviewStrong when roof obstructions are cleanly simplified
Orthophoto / roof planExclusion zones and documentationRequires stable scale and projection
DXF / DWGCAD planningUseful for technical layout teams
OBJ / FBX / GLBViewer or PV software importImport support depends on the target tool

Limits of yield statements

A 3D model can provide the local geometry for shading. Yield forecasting additionally requires weather data, system parameters, module and inverter data, soiling, wiring, and a simulation model.

NREL SAM describes external shading as irradiance reduction caused by nearby objects such as trees, buildings, roof obstructions, and other nearby elements.

No invented yield guarantee

The correct claim is a dependable geometric basis for PV planning, not a blanket percentage-loss promise.

Sun position, horizon, and source logic

Shading depends on sun position. NOAA provides azimuth and elevation for location, date, and time.

NREL SPA is a key reference for solar radiation applications, while PVGIS adds site-specific radiation and horizon handling. The 3D model describes local visible geometry; simulation tools handle yield modeling.

Frequently asked questions about PV shading from 3D models

Related

Build a PV shading basis from supplied imagery

We review your photos and prepare roof model, obstructions, orthophoto, or CAD handoff for clearer PV planning.

Article Tags

PV PlanningShading3D Roof ModelPhotogrammetryCAD