Orval Fairbairn wrote:
The solar cells to power it would consume a lot of its payload.

In the text "Airship Technology" Edited by Khoury and Gillett, Chapter 16,
"Solar Power" deals with design issues of solar powered airship proposals.

Using thin-film PV arrays and brushless DC motors, it states that:
"Potentially, the solar power system could weigh less than 10% of the gross
lift of the 22 tonne airship and would then be competitive in weight with
the conventional airship."