The National Geographic Institute (IGN) of Spain launched an innovative, open-source web-based Solar Potential Viewer to help citizens, solar installers, and public bodies assess whether installing solar panels is a viable option for any specific building. By simply entering an address, users can access detailed data such as roof area, maximum, and minimum solar potential, and an estimate of the annual energy production. The system calculates this by combining a digital terrain model, solar radiation data from PVGIS, and detailed building datasets from public administrations. The platform shows how Spain’s geographical advantages can support clean solar energy and makes public data actionable to drive greener choices and smart energy planning.