Are floating solar panels a thing? My naive assumption is that (most places) land is abundant enough that you can put solar panels everywhere. Dealing with the nature-hates-you-engineering of working with water seems like a method of last resort.
You get co-benefits of reducing water evaporation and plant growth (some places just use plastic balls for this same purpose) on the water side and on the solar side you get some cooling which increases efficiency.
For existing dams the ability to share the existing connections in an area that probably isn't flat except for the water is neat.
