They're still barely ankle deep in analysis to be honest.
Saharan sand has some not obvious from the outset effects on global climatic patterns (it's worth a look into).
More than 60 percent of the 1.5 billion tons of mineral-rich dust present in the earth's atmosphere comes from the Sahara. Individual dust clouds can reach a size of 500,000 square kilometers, an area equivalent to that of Spain. As these dust particles are only airborne for a short while, it's difficult to analyze the full extent of their impact.
How would a significant chunk of area under PV panelling ...
* survive abrasive desert conditions,
* alter local wind | sand movement patterns,
* affect other parts of the globe that until now had saharan sand as an input.