Auto-detect shading

How it works

On a clear morning, your panels produce a small trickle of power from indirect skylight, then jump the moment direct sunlight clears whatever sits on your eastern horizon. The same happens in reverse in the evening. The detector scans up to the last 180 days of your inverter’s data, finds those jumps on clear days, and notes exactly where the sun was in the sky — compass direction and elevation — at each one.

Each observation becomes a point on a horizon profile: a map of obstruction height around the full compass. A point only counts when at least two independent days agree — a stray cloud sitting on the horizon one morning can’t fake a tree. More history (and more seasons, since the sun rises and sets at different compass points through the year) widens the coverage and sharpens the profile.

What it needs

• An inverter linked to the layout — connect one from your account page if the button is disabled.
• Roughly ten reasonably clear days of history. Cloudy days are skipped automatically, so in a gloomy season the detector simply reaches further back in the window.

The first fit fetches your history from the inverter cloud and may take a few seconds; the data is cached, so running it again later is much faster.

Reading the result

A successful fit reports something like “Fitted 12 azimuth bins from 21 usable days (3 low-sample bins dropped)”. Bins are 5° compass slices with a confirmed obstruction height; usable days is how many clear days contributed; dropped bins are single-day observations discarded by the two-day rule. The bar also shows when the model was last fitted.

The fit also checks your production trend for panel soiling — a gradual drop against baseline that suggests your panels could use a clean — and reports what it finds alongside the fit message.

After the fit

The shading model is saved on the layout and the Apply shading model toggle switches on, so forecasts immediately account for your real horizon. Auto-detect also calibrates the forecast uncertainty band against your measured production. Worth re-running every few months: new seasons add compass coverage, and growing trees move horizons.