German company Tegrona introduced Tegrona Lite in September 2026, a free software tool that calculates solar module capacity directly from photographs. The application accepts drone photos, ground-level roof images, and roof plans, automatically determining roof geometry and generating photovoltaic system layouts without requiring CAD expertise or on-site measurement visits. The tool consolidates multiple workflow steps into a single browser-based application that processes ordinary photographs.
Tegrona Lite includes automated perspective correction designed for roof photographs taken from ground level. The software identifies vanishing points by analyzing roof tile geometry. Because roof tiles are parallel on actual rooftops, the software uses tile positions to calculate transformation geometry, enabling it to work with trapezoidal and triangular roof surfaces where simpler correction methods would fail. The application includes common European tile profiles including Frankfurter Pfanne and Hohlfalzziegel, plus custom entry capability for regional variants.
Users select their roof tile profile, and the software identifies and counts visible tiles to establish the pixel-to-dimension relationship. Alternatively, users enter a single known measurement such as roof window dimensions to establish scale.
Once roof geometry and scale are established, the algorithm distributes solar modules according to user-specified dimensions and power ratings. The software supports portrait orientation, landscape orientation, or combinations that optimize available space. For roofs that narrow toward the ridge, rows shift laterally and modules rotate to maximize capacity.
The system updates module count, total installed capacity, occupied area, and required clamps with each modification. PDF and PNG technical sheets display module arrangements overlaid on original photographs. Calculations run entirely locally on user devices, eliminating privacy concerns regarding geolocation metadata embedded in drone images.
Solar design software has become increasingly competitive throughout 2026. Established platforms including Aurora Solar, HelioScope, SurgePV, and PVsyst serve different market segments with pricing ranging from thousands annually to free tier options.
Tegrona Lite’s free availability creates competitive pressure while positioning the tool as a layout discovery tool rather than an engineering platform. The software explicitly excludes energy yield simulations, shading analysis, and structural checks.
Desktop applications support Windows 10 and later plus macOS 14 and later. The web version operates across platforms and devices. The tool is available in 11 languages including Spanish. No registration or internet connection is required for desktop processing, benefiting installers in regions with intermittent connectivity or limited digital infrastructure.
You can try it out for yourself here.
