They would be heat exchanging at a controlled rate so as to not give off noticeable (”cooling tower” -like) vapors above the barge or near outlets of the barge, in the waterway.
Probably they are relying upon the water current to disperse and move the heat further out to sea.
Google would have the leftists’ support.
Could also be relying upon current in order to drive a large waterwheel that has a horizontal instead of vertical rotation axis -— thus allowing the waterwheel to hide within the hull area.
Oops! Meant: vertical instead of horizontal rotation axis.