Drone Images for Solar Planning

Satellite data has a geometric resolution of 50 cm or more — far too imprecise for solar planning. Snow guards, vent pipes, and skylights simply aren't captured. A modern RTK drone, by contrast, achieves a GSD (Ground Sampling Distance) of 1–3 cm per pixel and maps every obstacle to scale.

The result: Error-free module layouts without costly re-planning. In practice, solar contractors save up to one hour of planning time per project — because the digital model already contains all dimensions, pitch angles, and obstacles.

For complex roofs with dormers, chimneys, or superstructures, drones are simply without alternative: satellite and aerial imagery is often years old and doesn't reflect the current state of the roof.

The quality of the 3D model stands or falls with the quality of the drone images. Those who know and follow the parameters below get a model directly usable in PV*SOL Premium — without manual rework.

GSD: Ground Sampling Distance

For solar planning, a GSD of less than 2 cm/pixel is the benchmark. With a typical 1-inch camera (12–20 MP), this means a flight altitude of 15–25 m above the ridge. RTK-equipped systems like the DJI Mavic 3E RTK achieve these values reliably even in gusty conditions.

≥ 80% front overlap and ≥ 70% side overlap are minimum requirements. For complex roofs with dormers or steep surfaces, additional oblique shots from 45° angles are recommended to avoid occlusions.

Standard GPS receivers deliver positional accuracies of 2–5 m and height accuracies of 5–10 m. For solar planning, where roof pitch and module area must be accurate to the centimeter, this is simply insufficient.

RTK (Real-Time Kinematic) and PPK (Post-Processing Kinematic) solve this problem through differential GPS correction. The result: 1–3 cm horizontal, 3–5 cm vertical — without placing a single ground control point (GCP).

PV*SOL Premium supports importing 3D building models in Wavefront OBJ format. The path from drone flight to imported model involves three clearly separated steps — and Voxelia 3D handles the entire middle part.

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   Automated Flight (5–20 Minutes)

   Mission planning apps like DJI Pilot 2 or Pix4Dcapture fully automate the flight. Parameters: 15–25 m altitude, 80% front overlap, 70% side overlap, additional oblique shots for complex roof shapes. Images are written directly to SD card or cloud storage.

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   Photogrammetric Processing

   Cloud platforms like Airteam or Pix4Dcloud process the imagery fully automatically into point cloud, mesh, and texture. Locally, Agisoft Metashape can be used. Voxelia 3D manually reviews the result: point cloud density, mesh quality, texture sharpness, and scale are checked and corrected as needed.

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   Import into PV*SOL Premium

   The final model is exported in Wavefront OBJ format and optimized for PV*SOL: correct scaling, north orientation, and roof surface assignment. If needed, the model is decimated in Blender to reduce polygon count. In PV*SOL Premium, the model can be activated with a double-click — no manual rework.

Those operating their own RTK drone for solar planning should budget a total first-year investment of approximately €4,000 (basic package) to €9,000 (pro package). Add ongoing software and insurance costs.

Voxelia 3D as a zero-investment alternative: from €45 per delivery — no hardware, no software subscription, no license. For businesses with fewer than 10 PV projects per month, owning a drone rarely pays off. Simply upload images and receive the PV-ready model.