Floating solar often seems like one of those 'solutions in search of a problem' type innovations to me, though it does seem like in the right niche (bodies of water where limiting the evaporation cycle is beneficial, for example; or bodies of water already right adjacent to transmission infrastructure like those used for hydropower) they provide a beneficial boost. The question is can they be a solution at a scale to really make a dent? 

"By now, it has become clear that there will not be a transition to clean energy sources without photovoltaics."

Clear to whom, Markus? The only people I've seen who feel that way are those selling and/or installing solar panels.
PV solar now generates 3% of the world's electricity, at uncertain times in uncertain weather, and remains hopelessly dependent on fossil fuel for backup. Any non-conflicted individual who feels dependence on fossil fuel represents some kind of "energy transition" hasn't been paying attention. That milestone was passed over a century ago.

And this will only get better as there is still significant curtailment of wind and solar in SA. With minimum gas generation rules being gradually lowered, more solar and wind coming on board and battery capacity doubling over the next 18 months SA should be running at an annualised 80% wind and solar within 12 months and 85% in 2023

Interesting points - curious about studies that these have on the ecosystems in the water.  Solar on roof tops and buildings make sense to me, but not sure about water.  Can you share any insights you have on this?