These solar cells are custom made for use in airships. Airships offer unique challenges for solar arrays. The solar cell mounting includes insulation to protect the envelope from the heat of the solar cells to reduce superheating. The cell mounting also needs to be strong enough to survive the inevitable jostling they will experience being mounted on the flexible envelope, particularly during inflation and deflation. And, of course, they must be extremely light. These 1.8 watt cells weigh about 4 grams each, including all mounting, reinforcements, and wiring.
What is the name of this solar battery element? Model? Manufacturer?