Why shading dominates production economics
A 10 kW system on a fully unshaded south-facing roof might produce 14,000 kWh/year. The same system with 30% shading (a single large oak on the south side) might produce 9,800 kWh/year — 30% less. The same homeowner usage now requires a 14 kW system to offset 100%, or accepting partial offset.
Two roofs that look identical from the curb can have dramatically different solar economics based on canopy + adjacent-structure shading patterns.
How shading analysis is typically performed
On-site shading instruments
Historically, on-site instruments like Solmetric SunEye or Solar Pathfinder captured the surrounding skyline at multiple roof points to plot sun-availability across the year. Still used for complex sites or final-design verification.
Aerial + 3D modeling (modern approach)
Google Solar API, Aurora Solar's HelioScope, and similar tools combine high-resolution aerial imagery with 3D building models + sun-position math to simulate sun exposure across the year. Faster + scalable for prospecting at volume. Most established installers use aerial modeling for proposal generation + on-site verification before final design.
What shading analysis flags
- Mature canopy on the south side — the biggest shading concern. Even partial canopy can reduce summer-peak production significantly.
- Adjacent two-story homes casting shadow on the target roof at certain hours.
- Chimneys + dormers + roof obstructions that block portions of the array.
- Seasonal sun-angle changes — winter low-sun-angle shading patterns differ from summer high-sun-angle patterns.
How Solar Launch incorporates shading
Every Solar Launch render uses Google Solar API rooftop geometry + sun-exposure modeling to estimate annual sun availability per roof facet. Heavily shaded facets are excluded from the panel-placement layout in the render; partially shaded facets are derated in the production estimate.
The customer portal's 25-year savings projection reflects local shading. Homeowners with heavy canopy see lower projected savings + smaller recommended system sizes — which sets honest expectations before the site survey.
Shading-aware system sizing on every render.
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