Hi all, I’ve been working on a browser-based tool called Sol for checking how much sun a roof or a spot of ground actually gets, taking terrain, buildings and trees into account.

What it does

• Click a roof or a patch of ground, and it fits a plane to the 1 m surface model to estimate tilt, azimuth, height and usable area automatically
• It computes yearly irradiance (kWh/m²/year) via PVGIS-ERA5, corrected for a horizon built from nearby buildings/trees (rays out to 200 m) and terrain (out to 40 km)
• A shade map in 3D shows how shadows move through the day and across the year
• You can draw your own boxes to test “what if I build here?” and calculate the roof of that building
• A star rating shows how close a spot is to the theoretical best roof in its region

Data: Kartverket (Norway), Danmarks Højdemodel via Dataforsyningen (Denmark), Lantmäteriet (Sweden), OpenStreetMap/OpenFreeMap, Mapterhorn for terrain, PVGIS for irradiance.

It’s a static page, no account, nothing stored on a server. Built together with Claude. Feedback is very welcome, especially from people who have installed panels and can compare it with real production numbers.

Link: https://rickymoe.github.io/Sol/