A they already built a solar aircraft and B they say it can scale to 50x the size and carry 50 people.  IMO, that would be more useful for lifting cargo vs people.<p>Second wing area and lift is related to velocity (not power) right before you stall outside of that it&#x27;s a looser connection.  Velocity is indirectly related to power in steady level flight based on drag.  Drag in level flight is a function of weight, shape, altitude, and velocity.<p>Economicly I don&#x27;t think this is a good idea. Physically it seems possible with cheaper and more efficemt solar cells it might make this more reasonable up to a point.  Especially if they can boost altitude and thus speed.