How big is a solar panel?Post author:freedomtask2Post published:January 15, 2020Post category:FAQThe average size of most panels for rooftop solar installation is about 65″(5.4 ft) by 39″(3.25ft) You Might Also Like Who invented solar panels? When were solar panels invented? January 15, 2020 Do solar panels save money? January 15, 2020 Roof-Mount System or Ground-Mount System January 15, 2020