What it is
SolarPosition.org is an independent, free service for solar geometry and off-grid solar planning. It started from a practical question: how should panels be set up for a house that has only the sun — not in June, when everything works, but in December? The answer needed exact sun positions, real climate data and a model honest enough to trust with a winter. This site is the result.
Principles
- Computed, not copied. Every figure on every page is calculated for its own place and date with published methods — see the methodology.
- No account, no tracking. Settings stay in your browser. See the privacy policy.
- Open data, credited. NASA POWER, the German Weather Service, GeoNames and OpenStreetMap make this possible.
How it is built
The server is a native Windows application written in Delphi, running behind Cloudflare. Pages are rendered on the server — charts included, as inline SVG — so they load fast and read well without JavaScript. The interactive map uses Leaflet and OpenStreetMap.
Contact
Corrections, ideas and data questions are welcome: [email protected].