Using Sun Hours

Updated 2 October 2026

These terms apply to the Sun Hours solar calculator and ChatGPT plugin operated by Andy. Support is available at support@sunhours.app.

What the calculator provides

The calculator gives a rough monthly and annual estimate using historical average sunlight on a horizontal surface, your system capacity and your loss assumption. It shows its data source and reference period with the result.

It does not model roof tilt, panel direction, nearby shading, snow or inverter limits. Results are not actual meter readings, a future weather forecast, an installation assessment, a quotation or a guarantee of energy or savings. Use your installer’s assessment and your equipment’s readings when making installation or operational decisions.

Availability and responsible use

The calculator is free to use. Source coverage and service availability can vary. Missing or unreadable data produces an unavailable result. Do not misuse the service, bypass request limits or use it to access data you are not entitled to use.

Data and ownership

Seasonal data comes from NASA POWER; UK postcode lookup comes from Postcodes.io. Sun Hours branding, Sol and the calculator interface belong to their respective rights holders. Source acknowledgements do not imply that NASA or other providers endorse Sun Hours.

Your rights and support

Nothing here excludes rights or remedies that cannot be excluded under applicable consumer law, or liability that cannot legally be limited. Contact support@sunhours.app if something is wrong with the service or a result.