3 ms·For the newest, most efficient panels, it's about 5 years.by vilda 14y agoFor the newest, most efficient panels, it's about 5 years.kitsune_ 14y agoWhere do you get this number from?jws 14y agoI don't have a number, but the exotics that are used in space applications may never pay back their production energy. But it takes a lot of extension cords to reach geosynchronous orbit.