Solar PV yield calculator
Calculate hourly PV output for the next 7 days from the real weather forecast (cloud cover, temperature), panel tilt and orientation.
System parameters
How it works
For the chosen location we fetch a solar-irradiance forecast from the ICON-EU and ECMWF models (Open-Meteo). We project hourly irradiance onto the plane of your panels (tilt and azimuth) and account for:
- Cell temperature — higher temperature lowers output. We use the NOCT model and a temperature coefficient of −0.4%/°C (typical mono-Si).
- System losses — inverter, wiring, soiling, LID. Combined factor 0.86 (PR ≈ 86%).
- Panel tilt and azimuth — for optimal output in Czechia we recommend a tilt of 30–40° and an azimuth of 0° (south). East–west installs have a flatter output through the day.
Values are indicative — actual output depends on the installation condition, shading, surrounding albedo and panel type. For a more precise calculation consult the manufacturer’s guidance or a professional.