I get the reason for preventing evaporation. > Reading many of the comments it sounds like preventing evaporation is the major reason for this. That's the imp

I get the reason for preventing evaporation. > Reading many of the comments it sounds like preventing evaporation is the major reason for this. That's the important part of the paragraph. I'm not asking about the evaporation, so much as why that's what everyone seems to thing the point of building the solar panels is? I would expect they were going to build them anyways, and the prevention of evaporation seems to be a bonus. But reading the other comments, it would appear that's a wrong assumption.