A little help with your sunshine
Updated 2 October 2026
For help with the calculator or ChatGPT plugin, email support@sunhours.app.
Choosing a location
Enter a complete UK postcode, such as BS1 5TR, or latitude and longitude separated by a comma. For Germany and the USA, use coordinates. Choose the returned location to load its seasonal sunlight.
Understanding the result
kWh is estimated energy. Peak sun hours describe an average day’s solar energy per square metre; they differ from daylight hours. The calculator uses a horizontal-sunlight baseline. Your roof angle, shading and installed equipment can change actual output.
If data is unavailable
Check the postcode or coordinates and try again. NASA POWER may be temporarily unavailable. If the issue persists, send the error text and approximate area to support. Never send passwords, API keys or inverter credentials.