They are asking the right questions: how can the wing be as large as possible, and how harnessing high altitude winds, while optimizing solar component?
Page 72:
“Wing area of 1000,000 m²: approximately 1,400 units
Wing area of 100,000 m²: approximately 14,000 units”
Page 71: they think that inflatable kites can scale more (“square-square” by their expression) than rigid kites (“square-cube law”). I suggested using shapewave® .