4. Commercial Instructions
All commercial site assessments should start with one rasterized flight pattern. Notably though, small commercial projects (i.e. < 150,000 sq ft) can follow the same flight instructions as residential properties.
Flight 1: Perimeter of property – “context flight”
Image Range: 150-400
Radius: Create a rasterized flight path inclusive of the building, plus any surrounding buildings, trees or structures that could cause shading on the proposed site of the solar project. The perimeter of the flight path should be set back 20 feet from the structure or relevant obstruction.
Camera angle: Nadir + structures mode turned on OR turn on 3D mode if site has many obstructions.
Altitude: Height of tallest surrounding structure or tree on site + 20 feet; if no tall structure or tree on site assume 100-150 feet.
Overlap: ~75% for front and side
Speed: ~5-8MPH, or taking a picture every 3-4 seconds.
Recommend App: DroneDeploy
Tip: DroneDeploy’s free app is a good choice for setting this flight path automatically.
Here are the specific DroneDeploy parameters for setting up the rasterized flight path:
For detailed flights, it is important to fly one or more POIs to capture 3D features of the site. This is the same process as Flight 3 for residential properties.
Flight 2: Perimeter of Obstructions (e.g. HVAC / Attic Fan / Vent Pipe / Tree) – second “Detailed flight”.
Image Range: 25 - 100
Radius: Inclusive of the cluster of obstructions or a singular, large or tall obstruction, like a chimney, cupula, HVAC unit or vent stack.
Camera angle: 15 – 30 degrees
Altitude: Height of obstruction on site + 10 feet
Overlap: >85%
Speed: ~2-4MPH, or taking a picture every 2-3 seconds.
Recommended App: DJI Go or Ground Station Pro
Tip: Mapping the 3D features of obstructions is critical for solar surveying and producing a high quality 3D model. Identify the cluster of obstructions and fly a POI around them, with the center of the cluster in frame. You may need to fly 2 or even 3 total Obstruction POIs depending on the complexity of the roof.
Here is an example of a large commercial project with many obstructions, hence the usage of 3D grid mode + POIs: